Refrigerant Circuit Pressures Specified Values, Vehicles Without Heat Pump

WARNING: This page is about a different variant/trim than selected.

Observe the test requirements. Refer to Pressures, Checking .

-- Pay attention to the pressure indicator (for example the pressure gauge) of the A/C service station.

NOTE:

The switching pressures for the activation of the Electrical A/C Compressor -V470- and the Radiator Fan -V7- /Radiator Fan 2 -V177- are vehicle-specific. Use the Vehicle Diagnostic Tester in the "Guided Fault Finding" function for the A/C system and the battery regulation.

Pressures must be measured at the service connections; the component location for these connections are vehicle-specific. Refer to

High-Pressure Side:

From the output pressure (when connecting the pressure gauge) raises up to maximum 20 bar (290 psi) pressure (depending on the ambient temperature and the operating conditions of the A/C system).

Low-Pressure Side:

Decreasing from initial pressure (when connecting the pressure gauges) to a value between 1.5 and 2.3 bar (21.76 to 33.36 psi) absolute pressure (depending on the required cooling output).

A/C Compressor Speed:

Depending on the required cooling output between 800 and 8500/min (currently a maximum of 5000/min for parked vehicles).

NOTE:

The temperature of the air downstream from evaporator, the current A/C compressor speed and the pressure of the refrigerant on the high pressure side depending on the vehicle are displayed by the different control modules (for example by the Front A/C Display Control Head -E87-, the Climatronic Control Module -J255-, the Thermal Management Control Module -J1024- or the A/C Control Module -J301-). Use the Vehicle Diagnostic Tester in the "Guided Fault Finding" function of the A/C system and the battery regulation.

If a high cooling output is required (for example, a high outside temperature and the blower speed set on high), then the A/C compressor will not bring the pressure on the low pressure side to the required value (for example, for a certain time after turning on the A/C). The A/C compressor is not actuated at the maximum specified speed (of approximately 8500/min) on a stationary or slow moving vehicle (up to a speed of approximately 45 km/h (28 mph)) (the A/C compressor speed is limited to approximately 5000/min). After a vehicle reaches a speed of more than approximately 45 km/h (28 mph), the limit for the maximum permissible A/C compressor speed is lifted. At a A/C compressor speed of 5000/min, a high outside temperature and a high fresh air blower speed (inefficient environmental controls), the A/C compressor output (the delivery volume) is no longer sufficient to reduce the pressure on the low pressure side to the target value. To check the A/C compressor control under these conditions, for example, the fresh air blower is activated only with approximately 40% of the maximum voltage, check the pressures at a lower fresh air blower speed. Use the Vehicle Diagnostic Tester in the "Guided Fault Finding" function for A/C system and the battery regulation. Refer to COOLING OUTPUT, CHECKING .

If there is a low cooling output (for example an exterior temperature of 20 °C (68 °F) and a low fresh air blower speed) the pressure on the high pressure side increases only to a value of 6 to 7 bar (87 to 101.5 psi) (the absence of energy is low, the refrigerant is quickly cooled in the condenser). To check the A/C compressor control and the pressure in the refrigerant circuit under these conditions for example the activating the fresh air blower with maximum voltage, adjusting the A/C system to maximum heat output and recirculating air mode. Use the Vehicle Diagnostic Tester in the "Guided Fault Finding" function of the A/C system. Refer to COOLING OUTPUT, CHECKING .

Under unfavorable conditions (very high ambient temperatures, high humidity), pressure on high-pressure side may increase to max. 29 bar (421 psi).

The specified speed of the A/C compressor depending on the vehicle is displayed from different control modules (for example by the Front A/C Display Control Head -E87-, Climatronic Control Module -J255- or the A/C Control Module -J301-). Use the Vehicle Diagnostic Tester in the "Guided Fault Finding" function of the A/C system.

The measured high pressure from different sensors (for example from the High Pressure Sensor -G65-, from the Refrigerant Circuit Pressure Sensor -G805- or the A/C Pressure/Temperature Sensor -G395-) is displayed by the vehicle (for example from the Front A/C Display Control Head -E87-, the A/C Control Module -J301-, the Thermal Management Control Module -J1024- or the Climatronic Control Module -J255-). Use the Vehicle Diagnostic Tester in the "Guided Fault Finding" function of the A/C system.

Depending on the A/C compressor speed and the control characteristic of the expansion valve, the low pressure settles within the A/C compressor output range in the tolerance range (1.5 to 2.3 bar (1.5 to 33.36 psi) positive pressure).

The specified speed of the A/C compressor must for this test be greater than 1500 RPM. Use the Vehicle Diagnostic Tester in the "Guided Fault Finding" function of the A/C compressor.

In setting "maximum cooling output" the target speed of the A/C compressor is regulated to approximately 4000 up to 5000/min. This value is vehicle-specific and is displayed as the measured value from the corresponding control module (for example from the display control head, the Front A/C Display Control Head -E87-, Climatronic Control Module -J255- or the Thermal Management Control Module -J1024-). Use the Vehicle Diagnostic Tester in the "Guided Fault Finding" function for the A/C system and the battery regulation.

At absolute pressure, 0 bar (0 psi) corresponds to absolute vacuum. Normal ambient pressure corresponds to 1 bar (14.5 psi) absolute pressure. On the scales of most pressure gauges, 0 bar (0 psi) corresponds to an absolute pressure of 1 bar (14.5 psi) (can be seen from -1 bar (-14.5 psi) mark below 0). Use the Vehicle Diagnostic Tester in the "Guided Fault Finding" function for the A/C System.

If, for a vehicle with two evaporators (one in the heater and A/C unit and one for battery cooling), the measured temperature on one of the evaporators corresponds to the specified value or the specified value falls short, but does not reach the required specified value on the other evaporator, the following adjustment is performed: the corresponding control module (for example battery regulation control module or the thermal management control module) activates the electric A/C compressor with increased speed (thereby increasing the A/C system cooling output and decreasing the pressure on the low pressure side as well as the evaporator temperature) via additional control modules (for example the electric drive power and control electronics and the A/C compressor control module). If on the evaporator the specified value for the temperature falls short, the corresponding control module (for example the battery regulation control module) activates the shut-off valve (for example the refrigerant shut-off valve 1 or the refrigerant shut-off valve 2) so that no more refrigerant flows through the evaporator which is too cold. Use the Vehicle Diagnostic Tester in the "Guided Fault Finding" function of the A/C system and the battery regulation. Refer to COOLING OUTPUT, CHECKING and OVERVIEW - A/C SYSTEM .

Because the output of the evaporator in the battery cooling module is noticeably smaller than the output of the evaporator in the heater and A/C unit, because of too little refrigerant in the circuit the required specified temperature in the battery cooling module may be reached but the specified temperature in the heater and A/C unit is no longer reached (although the A/C compressor is activated with a higher speed). Refer to COOLING OUTPUT, CHECKING and

Possible Deviation from Specified Value, the Cause and its Elimination
The required cooling output is not attained in the heater and A/C unit evaporator (and in the evaporator for battery cooling module). High pressure remains constant or increases only slightly (above pressure with engine stopped). Low pressure quickly drops to target value or lower.		Refer to ELECTRICALLY-DRIVEN A/C COMPRESSOR, CHECKING PRESSURE WITH A/C SYSTEM SWITCHED ON
The required cooling output is reached at first in the evaporator in the heater and A/C unit (and in the evaporator for battery cooling) after some time or after a longer running time the cooling output is no longer sufficient. The high pressure and low pressure are normal. After some time the high pressure raises above the specified value, the low pressure corresponds to the specified value or it falls under the specified value.		Refer to ELECTRICALLY-DRIVEN A/C COMPRESSOR, CHECKING PRESSURE WITH A/C SYSTEM SWITCHED ON
The required cooling output is not attained in the heater and A/C unit evaporator (and in the evaporator for battery cooling). The high pressure pipe corresponds to the specified value The low pressure is too low (lower than the target value)		Refer to ELECTRICALLY-DRIVEN A/C COMPRESSOR, CHECKING PRESSURE WITH A/C SYSTEM SWITCHED ON
The A/C compressor noise (particularly after switch-on) The required cooling output is not attained in the heater and A/C unit evaporator and/or in the evaporator for battery cooling. High pressure normal or too high Low pressure too high (the specified value is not reached,		Refer to ELECTRICALLY-DRIVEN A/C COMPRESSOR, CHECKING PRESSURE WITH A/C SYSTEM SWITCHED ON
The required cooling output is not attained in the heater and A/C unit evaporator (and in the evaporator for battery cooling). High pressure and low pressure are normal (correspond to the specified value)		Refer to ELECTRICALLY-DRIVEN A/C COMPRESSOR, CHECKING PRESSURE WITH A/C SYSTEM SWITCHED ON
The required cooling output is not attained in the heater and A/C unit evaporator (and in the evaporator for battery cooling). The high pressure pipe corresponds to the specified value The low pressure corresponds to the specified value or is too low		Refer to ELECTRICALLY-DRIVEN A/C COMPRESSOR, CHECKING PRESSURE WITH A/C SYSTEM SWITCHED ON
The required cooling output is not attained in the heater and A/C unit evaporator (and in the evaporator for battery cooling). The high pressure pipe corresponds to the specified value Low pressure quickly drops to specified value or lower.		Refer to ELECTRICALLY-DRIVEN A/C COMPRESSOR, CHECKING PRESSURE WITH A/C SYSTEM SWITCHED ON
The required cooling output is not attained in the heater and A/C unit evaporator (and in the evaporator for battery cooling). The required cooling output is only not attained at the heater and A/C unit evaporator (the cooling output on the evaporator for the cooling output is OK). The high pressure only falls slightly (via the pressure with the engine stopped) or corresponds to the specified value. Low pressure quickly drops to target value or lower.		Refer to ELECTRICALLY-DRIVEN A/C COMPRESSOR, CHECKING PRESSURE WITH A/C SYSTEM SWITCHED ON
The required cooling output is not attained in the heater and A/C unit evaporator (and in the evaporator for battery cooling). The high pressure increases above specification Low pressure quickly drops to specified value or lower.		Refer to ELECTRICALLY-DRIVEN A/C COMPRESSOR, CHECKING PRESSURE WITH A/C SYSTEM SWITCHED ON
The required cooling output is only not attained at the evaporator for the battery cooling module components (the cooling output at the heater and A/C unit evaporator is OK). The high pressure corresponds to the specified value or increases only slightly (above pressure with engine stopped). Low pressure drops to specified value or lower.		Refer to ELECTRICALLY-DRIVEN A/C COMPRESSOR, CHECKING PRESSURE WITH A/C SYSTEM SWITCHED ON
The required cooling output is not attained in the heater and A/C unit evaporator (and in the evaporator for battery cooling). The high pressure does not increase or only increases slightly above pressure with engine stopped. The low pressure does not drop or drops only slightly.		Refer to ELECTRICALLY-DRIVEN A/C COMPRESSOR, CHECKING PRESSURE WITH A/C SYSTEM SWITCHED ON

Possible Deviation from Specified Value During the Pressure Test
The required cooling output is not attained in the heater and A/C unit evaporator (and in the evaporator for battery cooling module). High pressure remains constant or increases only slightly (above pressure with A/C compressor stopped). Low pressure quickly drops to target value or lower.
Possible causes for the deviation from specified value and their solutions
There is too little refrigerant in the refrigerant circuit. -- Extract refrigerant from the refrigerant circuit. Refer to REFRIGERANT CIRCUIT, DISCHARGING .-- If the extracted refrigerant quantity is significantly less than the specified capacity (more that 100g (3.5 oz) less). Refer to TECHNICAL DATA , and look for leaks and correct. Refer to LEAKS, FINDING .-- The extracted refrigerant quantity corresponds approximately to the specified capacity, check the activation of the A/C compressor and the installed shut-off valve, if not malfunction is determined, replace the expansion valve for the evaporator in the heater and A/C unit. Refer to Refrigerant Circuit Refrigerant Circuit (R1234yf) Refrigerant Lines, Disconnecting And Connecting At A/C Compressor Refrigerant Circuit With Ignition Switched On, Checking Pressure Refrigerant Circuit Pressures And Temperatures Refrigerant Circuit, Cleaning Refrigerant, Filling In Reservoir Refrigerant Circuit, Charging Refrigerant Circuit, Evacuating Refrigerant Circuit, Discharging Refrigerant Gas Analysis, Performing Refrigerant Circuit, Flushing With Compressed Air Or Nitrogen Refrigerant Circuit, Cleaning Process Refrigerant Circuit, Cleaning Refrigerant Circuit, Finding Leaks Using Electronic Leak Detector Refrigerant Temperature Sensor Refrigerant Circuit Connections With Valve For Switches Refrigerant Circuit Pipes And Hoses Refrigerant Line With Inner Heat Exchanger Refrigerant Shut-Off Valves Refrigerant Circuit Layout And Function Refrigerant Circuit Components, Replacing Refrigerant R134a Vapor Pressure Table . The activation of the A/C compressor (and if equipped the refrigerant shut-off valve 1 and the refrigerant shut-off valve 2) is faulty. Use the Vehicle Diagnostic Tester in the "Guided Fault Finding" function for the A/C system and the battery regulation. Refer to COOLING OUTPUT, CHECKING , OVERVIEW - A/C SYSTEM and A/C Compressor A/C Compressor Regulator ValveN280 A/C Compressor Regulator Valve -N280-, Checking Switch-On Signal A/C Compressor Regulator ValveN280, Removing and Installing and Replacing A/C Service Station, Discharging A/C Service Station, Switching off and Disconnecting from Refrigerant Circuit A/C System, Operating after Charging A/C Service Station on Refrigerant Circuit, Connecting A/C Compressor, Replacing without the Need for Flushing Refrigerant Circuit A/C Pressure/Temperature Sensor A/C System, General Information . -- Check the activation and function of the A/C compressor (and if equipped the shut-off valves, for example the refrigerant shut-off valve 1, the refrigerant shut-off valve 2) and if necessary service. Use the Vehicle Diagnostic Tester in the "Guided Fault Finding" function of the A/C compressor and the battery regulation. If this is OK extract refrigerant from the refrigerant circuit. Refer to REFRIGERANT CIRCUIT, DISCHARGING . The expansion valve for the evaporator in the heater and A/C unit is faulty. Refer to Refrigerant Circuit Refrigerant Circuit (R1234yf) Refrigerant Lines, Disconnecting And Connecting At A/C Compressor Refrigerant Circuit With Ignition Switched On, Checking Pressure Refrigerant Circuit Pressures And Temperatures Refrigerant Circuit, Cleaning Refrigerant, Filling In Reservoir Refrigerant Circuit, Charging Refrigerant Circuit, Evacuating Refrigerant Circuit, Discharging Refrigerant Gas Analysis, Performing Refrigerant Circuit, Flushing With Compressed Air Or Nitrogen Refrigerant Circuit, Cleaning Process Refrigerant Circuit, Cleaning Refrigerant Circuit, Finding Leaks Using Electronic Leak Detector Refrigerant Temperature Sensor Refrigerant Circuit Connections With Valve For Switches Refrigerant Circuit Pipes And Hoses Refrigerant Line With Inner Heat Exchanger Refrigerant Shut-Off Valves Refrigerant Circuit Layout And Function Refrigerant Circuit Components, Replacing Refrigerant R134a Vapor Pressure Table for replacing. One if the refrigerant shut-off valves (if equipped) is faulty (closed), check the function. Use the Vehicle Diagnostic Tester in the "Guided Fault Finding" function for the A/C system and the battery regulation. Refer to Refrigerant Circuit Refrigerant Circuit (R1234yf) Refrigerant Lines, Disconnecting And Connecting At A/C Compressor Refrigerant Circuit With Ignition Switched On, Checking Pressure Refrigerant Circuit Pressures And Temperatures Refrigerant Circuit, Cleaning Refrigerant, Filling In Reservoir Refrigerant Circuit, Charging Refrigerant Circuit, Evacuating Refrigerant Circuit, Discharging Refrigerant Gas Analysis, Performing Refrigerant Circuit, Flushing With Compressed Air Or Nitrogen Refrigerant Circuit, Cleaning Process Refrigerant Circuit, Cleaning Refrigerant Circuit, Finding Leaks Using Electronic Leak Detector Refrigerant Temperature Sensor Refrigerant Circuit Connections With Valve For Switches Refrigerant Circuit Pipes And Hoses Refrigerant Line With Inner Heat Exchanger Refrigerant Shut-Off Valves Refrigerant Circuit Layout And Function Refrigerant Circuit Components, Replacing Refrigerant R134a Vapor Pressure Table for replacing. Constriction or blockage in the refrigerant circuit (for example in the refrigerant line between the "low pressure side" service connection and the A/C compressor). Refer to Refrigerant Circuit Refrigerant Circuit (R1234yf) Refrigerant Lines, Disconnecting And Connecting At A/C Compressor Refrigerant Circuit With Ignition Switched On, Checking Pressure Refrigerant Circuit Pressures And Temperatures Refrigerant Circuit, Cleaning Refrigerant, Filling In Reservoir Refrigerant Circuit, Charging Refrigerant Circuit, Evacuating Refrigerant Circuit, Discharging Refrigerant Gas Analysis, Performing Refrigerant Circuit, Flushing With Compressed Air Or Nitrogen Refrigerant Circuit, Cleaning Process Refrigerant Circuit, Cleaning Refrigerant Circuit, Finding Leaks Using Electronic Leak Detector Refrigerant Temperature Sensor Refrigerant Circuit Connections With Valve For Switches Refrigerant Circuit Pipes And Hoses Refrigerant Line With Inner Heat Exchanger Refrigerant Shut-Off Valves Refrigerant Circuit Layout And Function Refrigerant Circuit Components, Replacing Refrigerant R134a Vapor Pressure Table . -- If there is a blockage clean the refrigerant circuit (flush with refrigerant R1234yf). Refer to REFRIGERANT CIRCUIT, CLEANING .-- If the hose or pipe is kinked or constricted, replace this component. Refer to Refrigerant Circuit Refrigerant Circuit (R1234yf) Refrigerant Lines, Disconnecting And Connecting At A/C Compressor Refrigerant Circuit With Ignition Switched On, Checking Pressure Refrigerant Circuit Pressures And Temperatures Refrigerant Circuit, Cleaning Refrigerant, Filling In Reservoir Refrigerant Circuit, Charging Refrigerant Circuit, Evacuating Refrigerant Circuit, Discharging Refrigerant Gas Analysis, Performing Refrigerant Circuit, Flushing With Compressed Air Or Nitrogen Refrigerant Circuit, Cleaning Process Refrigerant Circuit, Cleaning Refrigerant Circuit, Finding Leaks Using Electronic Leak Detector Refrigerant Temperature Sensor Refrigerant Circuit Connections With Valve For Switches Refrigerant Circuit Pipes And Hoses Refrigerant Line With Inner Heat Exchanger Refrigerant Shut-Off Valves Refrigerant Circuit Layout And Function Refrigerant Circuit Components, Replacing Refrigerant R134a Vapor Pressure Table . The expansion valve for the evaporator in the heater and A/C unit is faulty. Refer to Refrigerant Circuit Refrigerant Circuit (R1234yf) Refrigerant Lines, Disconnecting And Connecting At A/C Compressor Refrigerant Circuit With Ignition Switched On, Checking Pressure Refrigerant Circuit Pressures And Temperatures Refrigerant Circuit, Cleaning Refrigerant, Filling In Reservoir Refrigerant Circuit, Charging Refrigerant Circuit, Evacuating Refrigerant Circuit, Discharging Refrigerant Gas Analysis, Performing Refrigerant Circuit, Flushing With Compressed Air Or Nitrogen Refrigerant Circuit, Cleaning Process Refrigerant Circuit, Cleaning Refrigerant Circuit, Finding Leaks Using Electronic Leak Detector Refrigerant Temperature Sensor Refrigerant Circuit Connections With Valve For Switches Refrigerant Circuit Pipes And Hoses Refrigerant Line With Inner Heat Exchanger Refrigerant Shut-Off Valves Refrigerant Circuit Layout And Function Refrigerant Circuit Components, Replacing Refrigerant R134a Vapor Pressure Table for replacing. A refrigerant shut-off valve is faulty (closed). Use the Vehicle Diagnostic Tester in the "Guided Fault Finding" function for the A/C system and the battery regulation. Refer to Refrigerant Circuit Refrigerant Circuit (R1234yf) Refrigerant Lines, Disconnecting And Connecting At A/C Compressor Refrigerant Circuit With Ignition Switched On, Checking Pressure Refrigerant Circuit Pressures And Temperatures Refrigerant Circuit, Cleaning Refrigerant, Filling In Reservoir Refrigerant Circuit, Charging Refrigerant Circuit, Evacuating Refrigerant Circuit, Discharging Refrigerant Gas Analysis, Performing Refrigerant Circuit, Flushing With Compressed Air Or Nitrogen Refrigerant Circuit, Cleaning Process Refrigerant Circuit, Cleaning Refrigerant Circuit, Finding Leaks Using Electronic Leak Detector Refrigerant Temperature Sensor Refrigerant Circuit Connections With Valve For Switches Refrigerant Circuit Pipes And Hoses Refrigerant Line With Inner Heat Exchanger Refrigerant Shut-Off Valves Refrigerant Circuit Layout And Function Refrigerant Circuit Components, Replacing Refrigerant R134a Vapor Pressure Table for replacing.
Final Procedures
-- Charge the refrigerant circuit. Refer to REFRIGERANT CIRCUIT, CHARGING .-- Repeat the test. Refer to ELECTRICALLY-DRIVEN A/C COMPRESSOR, CHECKING PRESSURE WITH A/C SYSTEM SWITCHED ON .

NOTE:

If for this complaint a malfunction is determined in the diagnostic, check the refrigerant circuit for a constriction or blockage (a constriction or a blockage in the refrigerant circuit can also lead to these complaints). If nothing is determined here, clean the refrigerant circuit (flush with refrigerant R1234yf). Refer to REFRIGERANT CIRCUIT, CLEANING .

Check the measured values of the sensors for Evaporator Vent Temperature Sensor -G263- and if equipped the temperature sensor before hybrid battery evaporator and the temperature sensor before hybrid battery evaporator as well at the activation of the A/C compressor via the corresponding control module. Use the Vehicle Diagnostic Tester in the "Guided Fault Finding" function for the A/C system and the battery regulation.

If there is an error in the measured value of the Evaporator Vent Temperature Sensor -G263-, the temperature sensor before hybrid battery evaporator or the temperature sensor after hybrid battery evaporator (depending on the vehicle use the Vehicle Diagnostic Tester in the "Guided Fault Finding" function for the A/C system and the battery regulation) this can lead to problems in the cooling output and the evaporator can freeze-up.

With a malfunction on one of the temperature sensors, the evaporator may ice up even though the quantity of refrigerant in the refrigerant circuit is OK.

If the A/C system function is not OK after repeating the test, for example after replacing expansion valve, clean the refrigerant circuit by flushing using the refrigerant R1234yf. Refer to REFRIGERANT CIRCUIT, CLEANING . Replace the A/C compressor and dryer cartridge (or reservoir/receiver/dryer). Refer to

If the expansion valve in the heater and A/C unit evaporator or the shut-off valve is faulty (permanently closed or does not open sufficiently), the A/C compressor is actuated to maximum output and the low pressure drops to specification or below (compressor draws off refrigerant from low-pressure side). Since the refrigerant cannot flow via the expansion valve, the cooling output is not attained, high pressure may also not increase or only increase slightly due to the absence of energy. Use the Vehicle Diagnostic Tester in the "Guided Fault Finding" Function for the A/C System and the Battery Regulation. Refer to

The evaporator in the heater and A/C Unit has considerably more output than the evaporator for battery cooling. The refrigerant shut-off valve 2 on the expansion valve in the battery cooling module depending on the version is activated for cooling the Electric Vehicle Battery -A2- (depending on the vehicle use the Vehicle Diagnostic Tester in the "Guided Fault Finding" function of the A/C system and the battery regulation) first after a specific battery temperature by the corresponding control module (for example from the battery regulation control module) so that the energy transformation via the evaporator for battery cooling is not or only slightly raised. Use the Vehicle Diagnostic Tester in the "Guided Fault Finding" function for the A/C system and the battery regulation. Refer to

Possible Deviation from Specified Value During the Pressure Test
The required cooling output is reached at first in the evaporator in the heater and A/C unit (and in the evaporator for battery cooling) after some time or after a longer running time the cooling output is no longer sufficient. The high pressure and low pressure are normal. After some time the high pressure raises above the specified value, the low pressure corresponds to the specified value or it falls under the specified value.
Possible causes for the deviation from specified value and their solutions
Radiator for coolant, condenser is contaminated or the activation of the radiator fan is not OK. -- Check the activation of the radiator fan and if necessary service. Use the Vehicle Diagnostic Tester in the "Guided Fault Finding" function of the A/C system.-- Check the condenser and radiator for the condenser for contamination and if necessary clean. Refer to Refrigerant Circuit Refrigerant Circuit (R1234yf) Refrigerant Lines, Disconnecting And Connecting At A/C Compressor Refrigerant Circuit With Ignition Switched On, Checking Pressure Refrigerant Circuit Pressures And Temperatures Refrigerant Circuit, Cleaning Refrigerant, Filling In Reservoir Refrigerant Circuit, Charging Refrigerant Circuit, Evacuating Refrigerant Circuit, Discharging Refrigerant Gas Analysis, Performing Refrigerant Circuit, Flushing With Compressed Air Or Nitrogen Refrigerant Circuit, Cleaning Process Refrigerant Circuit, Cleaning Refrigerant Circuit, Finding Leaks Using Electronic Leak Detector Refrigerant Temperature Sensor Refrigerant Circuit Connections With Valve For Switches Refrigerant Circuit Pipes And Hoses Refrigerant Line With Inner Heat Exchanger Refrigerant Shut-Off Valves Refrigerant Circuit Layout And Function Refrigerant Circuit Components, Replacing Refrigerant R134a Vapor Pressure Table and RADIATOR/RADIATOR FAN - CAED, CAEB, CPMB, CPMA RADIATOR/RADIATOR FAN - CABB, CABA, CABD, CAEA, CAEB, CDHB, CDNB, CDNC, CDHA, CDZA, CADA, CCUA, CFKA, CPMA, CAED, CPMB, CHJA, CPEA . Activation of function of the A/C compressor (or if equipped the refrigerant shut-off valve 1 or the refrigerant shut-off valve 2) is faulty. Moisture in refrigerant circuit -- Check the activation of the A/C compressor (and if equipped the refrigerant shut-off valve 1 and the refrigerant shut-off valve 2) and the measured value of the Evaporator Vent Temperature Sensor -G263-. Use the Vehicle Diagnostic Tester in the "Guided Fault Finding" function.-- If the activation of the A/C compressor (and if equipped the refrigerant shut-off valve 1 and the refrigerant shut-off valve 2) as well as the measured value of the Evaporator Vent Temperature Sensor -G263- is OK extract the refrigerant from the refrigerant circuit. Refer to REFRIGERANT CIRCUIT, DISCHARGING . Too much refrigerant in the refrigerant circuit Expansion valve malfunctioning If a shut-off valve installed in the refrigerant circuit does not open or opens incorrectly. Refer to Refrigerant Circuit Refrigerant Circuit (R1234yf) Refrigerant Lines, Disconnecting And Connecting At A/C Compressor Refrigerant Circuit With Ignition Switched On, Checking Pressure Refrigerant Circuit Pressures And Temperatures Refrigerant Circuit, Cleaning Refrigerant, Filling In Reservoir Refrigerant Circuit, Charging Refrigerant Circuit, Evacuating Refrigerant Circuit, Discharging Refrigerant Gas Analysis, Performing Refrigerant Circuit, Flushing With Compressed Air Or Nitrogen Refrigerant Circuit, Cleaning Process Refrigerant Circuit, Cleaning Refrigerant Circuit, Finding Leaks Using Electronic Leak Detector Refrigerant Temperature Sensor Refrigerant Circuit Connections With Valve For Switches Refrigerant Circuit Pipes And Hoses Refrigerant Line With Inner Heat Exchanger Refrigerant Shut-Off Valves Refrigerant Circuit Layout And Function Refrigerant Circuit Components, Replacing Refrigerant R134a Vapor Pressure Table . Moisture in refrigerant circuit -- Extract refrigerant from the refrigerant circuit. Refer to REFRIGERANT CIRCUIT, DISCHARGING .-- If the extracted refrigerant quantity is substantially greater (more than 100g (3.5 oz)) than the specified capacity there is too much refrigerant in the refrigerant circuit. Fill the refrigerant circuit and repeat the test. Refer to TECHNICAL DATA .-- If the extracted refrigerant quantity meets the specified capacity is only slightly greater than the specified capacity (maximum 100g (3.5 oz)) too much refrigerant oil is in the refrigerant circuit. Refer to TECHNICAL DATA . Clean the refrigerant circuit (flush with refrigerant R1234yf) and fill with the correct quantity of refrigerant and refrigerant oil and repeat the test. Refer to REFRIGERANT CIRCUIT, CLEANING .-- If equipped check the function of the installed shut-off valve. Refer to Refrigerant Circuit Refrigerant Circuit (R1234yf) Refrigerant Lines, Disconnecting And Connecting At A/C Compressor Refrigerant Circuit With Ignition Switched On, Checking Pressure Refrigerant Circuit Pressures And Temperatures Refrigerant Circuit, Cleaning Refrigerant, Filling In Reservoir Refrigerant Circuit, Charging Refrigerant Circuit, Evacuating Refrigerant Circuit, Discharging Refrigerant Gas Analysis, Performing Refrigerant Circuit, Flushing With Compressed Air Or Nitrogen Refrigerant Circuit, Cleaning Process Refrigerant Circuit, Cleaning Refrigerant Circuit, Finding Leaks Using Electronic Leak Detector Refrigerant Temperature Sensor Refrigerant Circuit Connections With Valve For Switches Refrigerant Circuit Pipes And Hoses Refrigerant Line With Inner Heat Exchanger Refrigerant Shut-Off Valves Refrigerant Circuit Layout And Function Refrigerant Circuit Components, Replacing Refrigerant R134a Vapor Pressure Table .-- Replace the expansion valve and desiccant bag/dryer cartridge (or reservoir/receiver/dryer). Refer to COMPONENTS, REPLACING and Refrigerant Circuit Refrigerant Circuit (R1234yf) Refrigerant Lines, Disconnecting And Connecting At A/C Compressor Refrigerant Circuit With Ignition Switched On, Checking Pressure Refrigerant Circuit Pressures And Temperatures Refrigerant Circuit, Cleaning Refrigerant, Filling In Reservoir Refrigerant Circuit, Charging Refrigerant Circuit, Evacuating Refrigerant Circuit, Discharging Refrigerant Gas Analysis, Performing Refrigerant Circuit, Flushing With Compressed Air Or Nitrogen Refrigerant Circuit, Cleaning Process Refrigerant Circuit, Cleaning Refrigerant Circuit, Finding Leaks Using Electronic Leak Detector Refrigerant Temperature Sensor Refrigerant Circuit Connections With Valve For Switches Refrigerant Circuit Pipes And Hoses Refrigerant Line With Inner Heat Exchanger Refrigerant Shut-Off Valves Refrigerant Circuit Layout And Function Refrigerant Circuit Components, Replacing Refrigerant R134a Vapor Pressure Table .
Final Procedures
-- Charge the refrigerant circuit. Refer to REFRIGERANT CIRCUIT, CHARGING .-- Repeat the test. Refer to ELECTRICALLY-DRIVEN A/C COMPRESSOR, CHECKING PRESSURE WITH A/C SYSTEM SWITCHED ON .

NOTE:

If too much refrigerant oil is located in the circuit, the A/C compressor must be discharges and replace the receiver/receiver/dryer (or dryer cartridge). Refer to

. After cleaning the refrigerant circuit (flushing with refrigerant R1234yf) fill it with the correct quantity of refrigerant oil in the refrigerant circuit. Refer to REFRIGERANT CIRCUIT, CLEANING and TECHNICAL DATA .

Check the measured values of the Evaporator Vent Temperature Sensor -G263- and the activation of the A/C compressor. If the measured value of the Evaporator Vent Temperature Sensor -G263- or the activation of the A/C compressor is faulty, the evaporator can freeze-up or the cooling output is not reached. Use the Vehicle Diagnostic Tester in the "Guided Fault Finding" function for the A/C system and the battery regulation. Refer to OVERVIEW - A/C SYSTEM and

With this malfunction, evaporator may ice up although the quantity of refrigerant in circuit is OK.

Likewise, the refrigerant circuit may become iced if there is a malfunction on the Evaporator Vent Temperature Sensor -G263- or/and on the temperature sensor after hybrid battery evaporator. For this concern also pay attention to the measured value of the Evaporator Vent Temperature Sensor -G263- and the temperature sensor after hybrid battery evaporator (on vehicles with battery cooling module). Use the Vehicle Diagnostic Tester in the "Guided Fault Finding" function of the A/C system and the battery regulation. Refer to OVERVIEW - A/C SYSTEM .

Possible Deviation from Specified Value during the Pressure Test
The required cooling output is not attained in the heater and A/C unit evaporator (and in the evaporator for battery cooling). The high pressure pipe corresponds to the specified value The low pressure is too low (lower than the target value)
Possible causes for the deviation from specified value and their solutions
There is too little refrigerant in the refrigerant circuit. -- Extract refrigerant from the refrigerant circuit. Refer to REFRIGERANT CIRCUIT, DISCHARGING .-- If the extracted refrigerant quantity is significantly less than the specified capacity (more that 100g (3.5 oz) less). Refer to TECHNICAL DATA , and look for leaks and correct. Refer to LEAKS, FINDING .-- The extracted refrigerant quantity corresponds approximately to the specified capacity, check the activation of the A/C compressor and the installed shut-off valve, if not malfunction is determined, replace the expansion valve for the evaporator in the heater and A/C unit. Refer to Refrigerant Circuit Refrigerant Circuit (R1234yf) Refrigerant Lines, Disconnecting And Connecting At A/C Compressor Refrigerant Circuit With Ignition Switched On, Checking Pressure Refrigerant Circuit Pressures And Temperatures Refrigerant Circuit, Cleaning Refrigerant, Filling In Reservoir Refrigerant Circuit, Charging Refrigerant Circuit, Evacuating Refrigerant Circuit, Discharging Refrigerant Gas Analysis, Performing Refrigerant Circuit, Flushing With Compressed Air Or Nitrogen Refrigerant Circuit, Cleaning Process Refrigerant Circuit, Cleaning Refrigerant Circuit, Finding Leaks Using Electronic Leak Detector Refrigerant Temperature Sensor Refrigerant Circuit Connections With Valve For Switches Refrigerant Circuit Pipes And Hoses Refrigerant Line With Inner Heat Exchanger Refrigerant Shut-Off Valves Refrigerant Circuit Layout And Function Refrigerant Circuit Components, Replacing Refrigerant R134a Vapor Pressure Table . Activation of function of the A/C compressor or if equipped the refrigerant shut-off valve 1 the refrigerant shut-off valve 2 is faulty. -- If no malfunction can be determined, check the activation and function of the A/C compressor and if equipped the refrigerant shut-off valve 1 the refrigerant shut-off valve 2. Use the Vehicle Diagnostic Tester in the "Guided Fault Finding" function for the A/C system and the battery regulation.-- Clean the refrigerant circuit (flush with refrigerant R1234yf). Refer to REFRIGERANT CIRCUIT, CLEANING . The expansion valve in the heater and A/C unit or if equipped the evaporator for battery cooling is faulty. -- Replace the expansion valve for the evaporator in the heater and A/C unit (and for the evaporator for battery cooling) as well as the desiccant bag/dryer cartridge (or receiver/receiver/dryer). A/C compressor faulty -- Replace the A/C compressor. Refer to COMPONENTS, REPLACING and A/C Compressor A/C Compressor Regulator ValveN280 A/C Compressor Regulator Valve -N280-, Checking Switch-On Signal A/C Compressor Regulator ValveN280, Removing and Installing and Replacing A/C Service Station, Discharging A/C Service Station, Switching off and Disconnecting from Refrigerant Circuit A/C System, Operating after Charging A/C Service Station on Refrigerant Circuit, Connecting A/C Compressor, Replacing without the Need for Flushing Refrigerant Circuit A/C Pressure/Temperature Sensor A/C System, General Information .-- If there is dirt in the refrigerant circuit, clean the refrigerant circuit (flush with refrigerant R1234yf) and replace the expansion valve and desiccant bag/dryer cartridge (or receiver/receiver/dryer). Refer to COMPONENTS, REPLACING and REFRIGERANT CIRCUIT, CLEANING .
Final Procedures
-- Charge the refrigerant circuit. Refer to REFRIGERANT CIRCUIT, CHARGING .-- Repeat the test. Refer to ELECTRICALLY-DRIVEN A/C COMPRESSOR, CHECKING PRESSURE WITH A/C SYSTEM SWITCHED ON .

NOTE:

For the malfunction "high pressure normal, low pressure too low" With this malfunction, evaporator may ice up, although quantity of refrigerant in circuit is OK.

If there is a malfunction an the refrigerant circuit, it was not activated and operates nevertheless, it is not necessary to clean the refrigerant circuit (flush with refrigerant R1234yf). Refer to REFRIGERANT CIRCUIT, CLEANING . For this error it is sufficient to replace the A/C compressor (pay attention to the refrigerant oil quantity in the A/C compressor). Refer to COMPONENTS, REPLACING and

If there is a fault in the A/C compressor (the A/C compressor is activated by the A/C compressor control module at too high of a speed), it is not necessary to clean the refrigerant circuit (flushing with refrigerant R1234yf). For this malfunction it is sufficient to replace the A/C compressor (pay attention to the refrigerant oil quantity in the A/C compressor). Refer to REFRIGERANT CIRCUIT, CLEANING , TECHNICAL DATA and

If the expansion valve (or one of the two expansion valves) is faulty (permanently closed or does not open sufficiently), the A/C compressor is also actuated to maximum output and the pressure on the low pressure side drops to specified value or below (compressor draws off refrigerant from the low-pressure side). Since the refrigerant cannot flow via the faulty expansion valve, the cooling output in the downstream evaporator is not attained and the high pressure may also not increase or only increase slightly due to the absence of energy. The A/C compressor may thereby be activated with a higher speed since the required cooling output is not attained in an evaporator. The same applies if the function or the activation of the refrigerant shut-off valve 1 or the refrigerant shut-off valve 2 is faulty. Use the Vehicle Diagnostic Tester in the "Guided Fault Finding" function for the A/C system and the battery regulation. Refer to

Check the measured values for the Evaporator Vent Temperature Sensor -G263- (and the measured values for the temperature sensor before hybrid battery evaporator and the temperature sensor after hybrid battery evaporator) as well as the activation of the A/C compressor by the A/C compressor control module. If the measured value of the Evaporator Vent Temperature Sensor -G263- (the temperature sensor before hybrid battery evaporator, the Temperature Sensor after Hybrid Battery Evaporator -G757-) or the activation of the A/C compressor is faulty, the evaporator can freeze-up or the required cooling output is not read. Use the Vehicle Diagnostic Tester in the "Guided Fault Finding" function for the A/C system and the battery regulation. Refer to OVERVIEW - A/C SYSTEM .

Possible Deviation from Specified Value During the Pressure Test
The A/C compressor noise (particularly after switch-on) The required cooling output is not attained in the heater and A/C unit evaporator and/or in the evaporator for battery cooling. High pressure normal or too high Low pressure too high (the specified value is not reached,
Possible causes for the deviation from specified value and their solutions
Activation of function of the A/C compressor or if equipped the refrigerant shut-off valve 1 the refrigerant shut-off valve 2 is faulty. Too much refrigerant or refrigerant oil in the refrigerant circuit -- Check the activation and function of the A/C compressor and if equipped the refrigerant shut-off valve 1 the refrigerant shut-off valve 2. Use the Vehicle Diagnostic Tester in the "Guided Fault Finding" function for the A/C system and the battery regulation and if necessary service. If no malfunction can be determined, extract the refrigerant from the refrigerant circuit. Refer to REFRIGERANT CIRCUIT, DISCHARGING .-- Extract refrigerant from the refrigerant circuit. Refer to REFRIGERANT CIRCUIT, DISCHARGING .-- If the extracted refrigerant quantity is substantially greater (more than 100g (3.5 oz)) than the specified capacity there is too much refrigerant in the refrigerant circuit. Fill the refrigerant circuit and repeat the test. Refer to TECHNICAL DATA .-- If the extracted refrigerant quantity meets the specified capacity is only slightly greater than the specified capacity (maximum 100g (3.5 oz)) too much refrigerant oil is in the refrigerant circuit. Refer to TECHNICAL DATA . Clean the refrigerant circuit (flush with refrigerant R1234yf) and fill with the correct quantity of refrigerant and refrigerant oil and repeat the test. Refer to REFRIGERANT CIRCUIT, CLEANING . Expansion valve malfunctioning -- Replace the expansion valve for the evaporator in the A/C unit (and for the evaporator for battery cooling) as well as the desiccant bag/dryer cartridge (or receiver/receiver/dryer). Refer to COMPONENTS, REPLACING and Refrigerant Circuit Refrigerant Circuit (R1234yf) Refrigerant Lines, Disconnecting And Connecting At A/C Compressor Refrigerant Circuit With Ignition Switched On, Checking Pressure Refrigerant Circuit Pressures And Temperatures Refrigerant Circuit, Cleaning Refrigerant, Filling In Reservoir Refrigerant Circuit, Charging Refrigerant Circuit, Evacuating Refrigerant Circuit, Discharging Refrigerant Gas Analysis, Performing Refrigerant Circuit, Flushing With Compressed Air Or Nitrogen Refrigerant Circuit, Cleaning Process Refrigerant Circuit, Cleaning Refrigerant Circuit, Finding Leaks Using Electronic Leak Detector Refrigerant Temperature Sensor Refrigerant Circuit Connections With Valve For Switches Refrigerant Circuit Pipes And Hoses Refrigerant Line With Inner Heat Exchanger Refrigerant Shut-Off Valves Refrigerant Circuit Layout And Function Refrigerant Circuit Components, Replacing Refrigerant R134a Vapor Pressure Table . A/C compressor faulty -- Replace the A/C compressor. Refer to COMPONENTS, REPLACING and A/C Compressor A/C Compressor Regulator ValveN280 A/C Compressor Regulator Valve -N280-, Checking Switch-On Signal A/C Compressor Regulator ValveN280, Removing and Installing and Replacing A/C Service Station, Discharging A/C Service Station, Switching off and Disconnecting from Refrigerant Circuit A/C System, Operating after Charging A/C Service Station on Refrigerant Circuit, Connecting A/C Compressor, Replacing without the Need for Flushing Refrigerant Circuit A/C Pressure/Temperature Sensor A/C System, General Information .-- If there is dirt in the refrigerant circuit, clean the refrigerant circuit (flush with refrigerant R1234yf) and replace the expansion valve and desiccant bag/dryer cartridge (or receiver/receiver/dryer). Refer to COMPONENTS, REPLACING and REFRIGERANT CIRCUIT, CLEANING .
Final Procedures
-- Charge the refrigerant circuit. Refer to REFRIGERANT CIRCUIT, CHARGING .-- Repeat the test. Refer to ELECTRICALLY-DRIVEN A/C COMPRESSOR, CHECKING PRESSURE WITH A/C SYSTEM SWITCHED ON .

NOTE:

This fault may also be caused by too much refrigerant oil in the refrigerant circuit. Overfilling with refrigerant oil can occur if, for example, the compressor has been replaced without adjusting the quantity of refrigerant oil. Refer to COMPONENTS, REPLACING and TECHNICAL DATA . If there is too much refrigerant oil in the refrigerant circuit, clean the refrigerant circuit (flush with refrigerant R1234yf). Refer to REFRIGERANT CIRCUIT, CLEANING .

If the expansion valve for the heater and A/C unit evaporator (or for the evaporator in the battery cooling) is faulty (permanently closed or does not open sufficiently), the A/C compressor is actuated to maximum output and the low pressure drops to the target value or below (compressor draws off refrigerant from low-pressure side). Since the refrigerant cannot flow via the expansion valve, the cooling output is not attained and the high pressure may also not increase or only increase slightly due to the absence of energy. The same applies if the function or the activation of the refrigerant shut-off valve 1 or the refrigerant shut-off valve 2 is faulty. Use the Vehicle Diagnostic Tester in the "Guided Fault Finding" function for the A/C system and the battery regulation. Refer to

Possible Deviation from Specified Value during the Pressure Test
The required cooling output is not attained in the heater and A/C unit evaporator (and in the evaporator for battery cooling). High pressure and low pressure are normal (correspond to the specified value)
Possible causes for the deviation from specified value and their solutions
Activation of function of the A/C compressor and if equipped the refrigerant shut-off valve 1 or the refrigerant shut-off valve 2 is faulty. Not enough refrigerant in the refrigerant circuit. -- Check the activation and function of the A/C compressor and if equipped the refrigerant shut-off valve 1 the refrigerant shut-off valve 2. Use the Vehicle Diagnostic Tester in the "Guided Fault Finding" function for the A/C system and the battery regulation and if necessary service. Refer to Refrigerant Circuit Refrigerant Circuit (R1234yf) Refrigerant Lines, Disconnecting And Connecting At A/C Compressor Refrigerant Circuit With Ignition Switched On, Checking Pressure Refrigerant Circuit Pressures And Temperatures Refrigerant Circuit, Cleaning Refrigerant, Filling In Reservoir Refrigerant Circuit, Charging Refrigerant Circuit, Evacuating Refrigerant Circuit, Discharging Refrigerant Gas Analysis, Performing Refrigerant Circuit, Flushing With Compressed Air Or Nitrogen Refrigerant Circuit, Cleaning Process Refrigerant Circuit, Cleaning Refrigerant Circuit, Finding Leaks Using Electronic Leak Detector Refrigerant Temperature Sensor Refrigerant Circuit Connections With Valve For Switches Refrigerant Circuit Pipes And Hoses Refrigerant Line With Inner Heat Exchanger Refrigerant Shut-Off Valves Refrigerant Circuit Layout And Function Refrigerant Circuit Components, Replacing Refrigerant R134a Vapor Pressure Table . If no malfunction can be determined, extract the refrigerant from the refrigerant circuit.-- Extract refrigerant from the refrigerant circuit. Refer to REFRIGERANT CIRCUIT, DISCHARGING .-- If the extracted refrigerant quantity is significantly less than the specified capacity (more that 100g (3.5 oz) less). Refer to TECHNICAL DATA , and look for leaks and correct. Refer to LEAKS, FINDING .-- If the extracted refrigerant quantity corresponds to the specified capacity or is only slightly smaller (maximum 100g (3.5 oz)) the expansion valve for the evaporator or a shut-off valve installed in the heater and A/C unit is faulty. Refer to TECHNICAL DATA . The expansion valve for the evaporator in the heater and A/C unit is faulty. Refer to Refrigerant Circuit Refrigerant Circuit (R1234yf) Refrigerant Lines, Disconnecting And Connecting At A/C Compressor Refrigerant Circuit With Ignition Switched On, Checking Pressure Refrigerant Circuit Pressures And Temperatures Refrigerant Circuit, Cleaning Refrigerant, Filling In Reservoir Refrigerant Circuit, Charging Refrigerant Circuit, Evacuating Refrigerant Circuit, Discharging Refrigerant Gas Analysis, Performing Refrigerant Circuit, Flushing With Compressed Air Or Nitrogen Refrigerant Circuit, Cleaning Process Refrigerant Circuit, Cleaning Refrigerant Circuit, Finding Leaks Using Electronic Leak Detector Refrigerant Temperature Sensor Refrigerant Circuit Connections With Valve For Switches Refrigerant Circuit Pipes And Hoses Refrigerant Line With Inner Heat Exchanger Refrigerant Shut-Off Valves Refrigerant Circuit Layout And Function Refrigerant Circuit Components, Replacing Refrigerant R134a Vapor Pressure Table . A refrigerant shut-off valves (if equipped) is faulty (closed), check the function. Use the Vehicle Diagnostic Tester in the "Guided Fault Finding" function for the A/C system and the battery regulation. Refer to Refrigerant Circuit Refrigerant Circuit (R1234yf) Refrigerant Lines, Disconnecting And Connecting At A/C Compressor Refrigerant Circuit With Ignition Switched On, Checking Pressure Refrigerant Circuit Pressures And Temperatures Refrigerant Circuit, Cleaning Refrigerant, Filling In Reservoir Refrigerant Circuit, Charging Refrigerant Circuit, Evacuating Refrigerant Circuit, Discharging Refrigerant Gas Analysis, Performing Refrigerant Circuit, Flushing With Compressed Air Or Nitrogen Refrigerant Circuit, Cleaning Process Refrigerant Circuit, Cleaning Refrigerant Circuit, Finding Leaks Using Electronic Leak Detector Refrigerant Temperature Sensor Refrigerant Circuit Connections With Valve For Switches Refrigerant Circuit Pipes And Hoses Refrigerant Line With Inner Heat Exchanger Refrigerant Shut-Off Valves Refrigerant Circuit Layout And Function Refrigerant Circuit Components, Replacing Refrigerant R134a Vapor Pressure Table for replacing. -- If equipped check the function of the installed shut-off valve. Refer to Refrigerant Circuit Refrigerant Circuit (R1234yf) Refrigerant Lines, Disconnecting And Connecting At A/C Compressor Refrigerant Circuit With Ignition Switched On, Checking Pressure Refrigerant Circuit Pressures And Temperatures Refrigerant Circuit, Cleaning Refrigerant, Filling In Reservoir Refrigerant Circuit, Charging Refrigerant Circuit, Evacuating Refrigerant Circuit, Discharging Refrigerant Gas Analysis, Performing Refrigerant Circuit, Flushing With Compressed Air Or Nitrogen Refrigerant Circuit, Cleaning Process Refrigerant Circuit, Cleaning Refrigerant Circuit, Finding Leaks Using Electronic Leak Detector Refrigerant Temperature Sensor Refrigerant Circuit Connections With Valve For Switches Refrigerant Circuit Pipes And Hoses Refrigerant Line With Inner Heat Exchanger Refrigerant Shut-Off Valves Refrigerant Circuit Layout And Function Refrigerant Circuit Components, Replacing Refrigerant R134a Vapor Pressure Table .-- Replace the expansion valve for the evaporator in the heater and A/C unit. Refer to Refrigerant Circuit Refrigerant Circuit (R1234yf) Refrigerant Lines, Disconnecting And Connecting At A/C Compressor Refrigerant Circuit With Ignition Switched On, Checking Pressure Refrigerant Circuit Pressures And Temperatures Refrigerant Circuit, Cleaning Refrigerant, Filling In Reservoir Refrigerant Circuit, Charging Refrigerant Circuit, Evacuating Refrigerant Circuit, Discharging Refrigerant Gas Analysis, Performing Refrigerant Circuit, Flushing With Compressed Air Or Nitrogen Refrigerant Circuit, Cleaning Process Refrigerant Circuit, Cleaning Refrigerant Circuit, Finding Leaks Using Electronic Leak Detector Refrigerant Temperature Sensor Refrigerant Circuit Connections With Valve For Switches Refrigerant Circuit Pipes And Hoses Refrigerant Line With Inner Heat Exchanger Refrigerant Shut-Off Valves Refrigerant Circuit Layout And Function Refrigerant Circuit Components, Replacing Refrigerant R134a Vapor Pressure Table . Too much refrigerant oil in the refrigerant circuit -- Clean the refrigerant circuit (flush with refrigerant R1234yf). Refer to REFRIGERANT CIRCUIT, CLEANING .-- Replace the expansion valve for the evaporator in the A/C unit (and for the evaporator for battery cooling) as well as the desiccant bag/dryer cartridge (or receiver/receiver/dryer). Refer to COMPONENTS, REPLACING and Refrigerant Circuit Refrigerant Circuit (R1234yf) Refrigerant Lines, Disconnecting And Connecting At A/C Compressor Refrigerant Circuit With Ignition Switched On, Checking Pressure Refrigerant Circuit Pressures And Temperatures Refrigerant Circuit, Cleaning Refrigerant, Filling In Reservoir Refrigerant Circuit, Charging Refrigerant Circuit, Evacuating Refrigerant Circuit, Discharging Refrigerant Gas Analysis, Performing Refrigerant Circuit, Flushing With Compressed Air Or Nitrogen Refrigerant Circuit, Cleaning Process Refrigerant Circuit, Cleaning Refrigerant Circuit, Finding Leaks Using Electronic Leak Detector Refrigerant Temperature Sensor Refrigerant Circuit Connections With Valve For Switches Refrigerant Circuit Pipes And Hoses Refrigerant Line With Inner Heat Exchanger Refrigerant Shut-Off Valves Refrigerant Circuit Layout And Function Refrigerant Circuit Components, Replacing Refrigerant R134a Vapor Pressure Table .
Final Procedures
-- Charge the refrigerant circuit. Refer to REFRIGERANT CIRCUIT, CHARGING .-- Repeat the test. Refer to ELECTRICALLY-DRIVEN A/C COMPRESSOR, CHECKING PRESSURE WITH A/C SYSTEM SWITCHED ON .

NOTE:

Possible Deviation from Specified Value during the Pressure Test
The required cooling output is not attained in the heater and A/C unit evaporator (and in the evaporator for battery cooling). The high pressure pipe corresponds to the specified value The low pressure corresponds to the specified value or is too low
Possible causes for the deviation from specified value and their solutions
The activation of the A/C compressor and if equipped the refrigerant shut-off valve 1 the refrigerant shut-off valve 2 is faulty. Use the Vehicle Diagnostic Tester in the "Guided Fault Finding" function for the A/C system and the battery regulation. -- Check the activation and function of the A/C compressor (and if equipped the refrigerant shut-off valve 1 and the refrigerant shut-off valve 2) and if necessary service. Use the Vehicle Diagnostic Tester in the "Guided Fault Finding" function of the A/C compressor and the battery regulation. If this is OK extract refrigerant from the refrigerant circuit. There is too little refrigerant in the refrigerant circuit. -- Extract refrigerant from the refrigerant circuit. Refer to REFRIGERANT CIRCUIT, DISCHARGING .-- If the extracted refrigerant quantity is significantly less than the specified capacity (more that 100g (3.5 oz)). Refer to TECHNICAL DATA , and look for leaks and correct. Refer to LEAKS, FINDING .-- If the extracted refrigerant quantity corresponds to the specified capacity or is only slightly smaller (less than 100g (3.5 oz)). Refer to TECHNICAL DATA and TECHNICAL DATA . Check the refrigerant shut-off valve for function. Refer to the Refrigerant Circuit Refrigerant Circuit (R1234yf) Refrigerant Lines, Disconnecting And Connecting At A/C Compressor Refrigerant Circuit With Ignition Switched On, Checking Pressure Refrigerant Circuit Pressures And Temperatures Refrigerant Circuit, Cleaning Refrigerant, Filling In Reservoir Refrigerant Circuit, Charging Refrigerant Circuit, Evacuating Refrigerant Circuit, Discharging Refrigerant Gas Analysis, Performing Refrigerant Circuit, Flushing With Compressed Air Or Nitrogen Refrigerant Circuit, Cleaning Process Refrigerant Circuit, Cleaning Refrigerant Circuit, Finding Leaks Using Electronic Leak Detector Refrigerant Temperature Sensor Refrigerant Circuit Connections With Valve For Switches Refrigerant Circuit Pipes And Hoses Refrigerant Line With Inner Heat Exchanger Refrigerant Shut-Off Valves Refrigerant Circuit Layout And Function Refrigerant Circuit Components, Replacing Refrigerant R134a Vapor Pressure Table . The expansion valve for the evaporator in the heater and A/C unit is faulty. Refer to Refrigerant Circuit Refrigerant Circuit (R1234yf) Refrigerant Lines, Disconnecting And Connecting At A/C Compressor Refrigerant Circuit With Ignition Switched On, Checking Pressure Refrigerant Circuit Pressures And Temperatures Refrigerant Circuit, Cleaning Refrigerant, Filling In Reservoir Refrigerant Circuit, Charging Refrigerant Circuit, Evacuating Refrigerant Circuit, Discharging Refrigerant Gas Analysis, Performing Refrigerant Circuit, Flushing With Compressed Air Or Nitrogen Refrigerant Circuit, Cleaning Process Refrigerant Circuit, Cleaning Refrigerant Circuit, Finding Leaks Using Electronic Leak Detector Refrigerant Temperature Sensor Refrigerant Circuit Connections With Valve For Switches Refrigerant Circuit Pipes And Hoses Refrigerant Line With Inner Heat Exchanger Refrigerant Shut-Off Valves Refrigerant Circuit Layout And Function Refrigerant Circuit Components, Replacing Refrigerant R134a Vapor Pressure Table . A refrigerant shut-off valve is faulty (closed). Use the Vehicle Diagnostic Tester in the "Guided Fault Finding" function for the A/C system and the battery regulation. Refer to Refrigerant Circuit Refrigerant Circuit (R1234yf) Refrigerant Lines, Disconnecting And Connecting At A/C Compressor Refrigerant Circuit With Ignition Switched On, Checking Pressure Refrigerant Circuit Pressures And Temperatures Refrigerant Circuit, Cleaning Refrigerant, Filling In Reservoir Refrigerant Circuit, Charging Refrigerant Circuit, Evacuating Refrigerant Circuit, Discharging Refrigerant Gas Analysis, Performing Refrigerant Circuit, Flushing With Compressed Air Or Nitrogen Refrigerant Circuit, Cleaning Process Refrigerant Circuit, Cleaning Refrigerant Circuit, Finding Leaks Using Electronic Leak Detector Refrigerant Temperature Sensor Refrigerant Circuit Connections With Valve For Switches Refrigerant Circuit Pipes And Hoses Refrigerant Line With Inner Heat Exchanger Refrigerant Shut-Off Valves Refrigerant Circuit Layout And Function Refrigerant Circuit Components, Replacing Refrigerant R134a Vapor Pressure Table . -- If equipped check the function of the installed shut-off valve. Refer to Refrigerant Circuit Refrigerant Circuit (R1234yf) Refrigerant Lines, Disconnecting And Connecting At A/C Compressor Refrigerant Circuit With Ignition Switched On, Checking Pressure Refrigerant Circuit Pressures And Temperatures Refrigerant Circuit, Cleaning Refrigerant, Filling In Reservoir Refrigerant Circuit, Charging Refrigerant Circuit, Evacuating Refrigerant Circuit, Discharging Refrigerant Gas Analysis, Performing Refrigerant Circuit, Flushing With Compressed Air Or Nitrogen Refrigerant Circuit, Cleaning Process Refrigerant Circuit, Cleaning Refrigerant Circuit, Finding Leaks Using Electronic Leak Detector Refrigerant Temperature Sensor Refrigerant Circuit Connections With Valve For Switches Refrigerant Circuit Pipes And Hoses Refrigerant Line With Inner Heat Exchanger Refrigerant Shut-Off Valves Refrigerant Circuit Layout And Function Refrigerant Circuit Components, Replacing Refrigerant R134a Vapor Pressure Table .-- Replace the expansion valve for the evaporator in the heater and A/C unit. Refer to Refrigerant Circuit Refrigerant Circuit (R1234yf) Refrigerant Lines, Disconnecting And Connecting At A/C Compressor Refrigerant Circuit With Ignition Switched On, Checking Pressure Refrigerant Circuit Pressures And Temperatures Refrigerant Circuit, Cleaning Refrigerant, Filling In Reservoir Refrigerant Circuit, Charging Refrigerant Circuit, Evacuating Refrigerant Circuit, Discharging Refrigerant Gas Analysis, Performing Refrigerant Circuit, Flushing With Compressed Air Or Nitrogen Refrigerant Circuit, Cleaning Process Refrigerant Circuit, Cleaning Refrigerant Circuit, Finding Leaks Using Electronic Leak Detector Refrigerant Temperature Sensor Refrigerant Circuit Connections With Valve For Switches Refrigerant Circuit Pipes And Hoses Refrigerant Line With Inner Heat Exchanger Refrigerant Shut-Off Valves Refrigerant Circuit Layout And Function Refrigerant Circuit Components, Replacing Refrigerant R134a Vapor Pressure Table . Too much refrigerant oil in the refrigerant circuit -- Clean the refrigerant circuit (flush with refrigerant R1234yf). Refer to REFRIGERANT CIRCUIT, CLEANING .-- Replace the expansion valve for the evaporator in the A/C unit (and for the evaporator for battery cooling) as well as the desiccant bag/dryer cartridge (or receiver/receiver/dryer). Refer to COMPONENTS, REPLACING and Refrigerant Circuit Refrigerant Circuit (R1234yf) Refrigerant Lines, Disconnecting And Connecting At A/C Compressor Refrigerant Circuit With Ignition Switched On, Checking Pressure Refrigerant Circuit Pressures And Temperatures Refrigerant Circuit, Cleaning Refrigerant, Filling In Reservoir Refrigerant Circuit, Charging Refrigerant Circuit, Evacuating Refrigerant Circuit, Discharging Refrigerant Gas Analysis, Performing Refrigerant Circuit, Flushing With Compressed Air Or Nitrogen Refrigerant Circuit, Cleaning Process Refrigerant Circuit, Cleaning Refrigerant Circuit, Finding Leaks Using Electronic Leak Detector Refrigerant Temperature Sensor Refrigerant Circuit Connections With Valve For Switches Refrigerant Circuit Pipes And Hoses Refrigerant Line With Inner Heat Exchanger Refrigerant Shut-Off Valves Refrigerant Circuit Layout And Function Refrigerant Circuit Components, Replacing Refrigerant R134a Vapor Pressure Table .
Final Procedures
-- Charge the refrigerant circuit. Refer to REFRIGERANT CIRCUIT, CHARGING .-- Repeat the test. Refer to ELECTRICALLY-DRIVEN A/C COMPRESSOR, CHECKING PRESSURE WITH A/C SYSTEM SWITCHED ON .

NOTE:

Pay attention to previous notes.

Possible Deviation from Specified Value During the Pressure Test
The required cooling output is not attained in the heater and A/C unit evaporator (and in the evaporator for battery cooling). The high pressure pipe corresponds to the specified value Low pressure quickly drops to specified value or lower.
Possible causes for the deviation from specified value and their solutions
A/C compressor activation or functionality malfunctioning. Constriction or obstruction in refrigerant circuit -- Check the activation and function of the A/C compressor and service. Use the Vehicle Diagnostic Tester in the "Guided Fault Finding" function of the A/C system and the battery regulation. If not error can be determined run hand over refrigerant circuit to check for differences in temperature. Refer to Refrigerant Circuit Refrigerant Circuit (R1234yf) Refrigerant Lines, Disconnecting And Connecting At A/C Compressor Refrigerant Circuit With Ignition Switched On, Checking Pressure Refrigerant Circuit Pressures And Temperatures Refrigerant Circuit, Cleaning Refrigerant, Filling In Reservoir Refrigerant Circuit, Charging Refrigerant Circuit, Evacuating Refrigerant Circuit, Discharging Refrigerant Gas Analysis, Performing Refrigerant Circuit, Flushing With Compressed Air Or Nitrogen Refrigerant Circuit, Cleaning Process Refrigerant Circuit, Cleaning Refrigerant Circuit, Finding Leaks Using Electronic Leak Detector Refrigerant Temperature Sensor Refrigerant Circuit Connections With Valve For Switches Refrigerant Circuit Pipes And Hoses Refrigerant Line With Inner Heat Exchanger Refrigerant Shut-Off Valves Refrigerant Circuit Layout And Function Refrigerant Circuit Components, Replacing Refrigerant R134a Vapor Pressure Table .-- If difference in temperature is found at one component: If the hose or pipe is kinked or constricted, replace this component. Refer to Refrigerant Circuit Refrigerant Circuit (R1234yf) Refrigerant Lines, Disconnecting And Connecting At A/C Compressor Refrigerant Circuit With Ignition Switched On, Checking Pressure Refrigerant Circuit Pressures And Temperatures Refrigerant Circuit, Cleaning Refrigerant, Filling In Reservoir Refrigerant Circuit, Charging Refrigerant Circuit, Evacuating Refrigerant Circuit, Discharging Refrigerant Gas Analysis, Performing Refrigerant Circuit, Flushing With Compressed Air Or Nitrogen Refrigerant Circuit, Cleaning Process Refrigerant Circuit, Cleaning Refrigerant Circuit, Finding Leaks Using Electronic Leak Detector Refrigerant Temperature Sensor Refrigerant Circuit Connections With Valve For Switches Refrigerant Circuit Pipes And Hoses Refrigerant Line With Inner Heat Exchanger Refrigerant Shut-Off Valves Refrigerant Circuit Layout And Function Refrigerant Circuit Components, Replacing Refrigerant R134a Vapor Pressure Table . If there is a blockage clean the refrigerant circuit (flush with refrigerant R1234yf). Refer to REFRIGERANT CIRCUIT, CLEANING . There is too little refrigerant in the refrigerant circuit. -- Extract refrigerant from the refrigerant circuit. Refer to REFRIGERANT CIRCUIT, DISCHARGING .-- If the extracted refrigerant quantity is significantly less than the specified capacity (more that 100g (3.5 oz). Refer to TECHNICAL DATA , and look for leaks and correct. Refer to LEAKS, FINDING .-- If the extracted refrigerant quantity corresponds to the capacity or is only slightly smaller (maximum 100g (3.5 oz)) check the expansion valve and shut-off valve for function. Refer to TECHNICAL DATA and Refrigerant Circuit Refrigerant Circuit (R1234yf) Refrigerant Lines, Disconnecting And Connecting At A/C Compressor Refrigerant Circuit With Ignition Switched On, Checking Pressure Refrigerant Circuit Pressures And Temperatures Refrigerant Circuit, Cleaning Refrigerant, Filling In Reservoir Refrigerant Circuit, Charging Refrigerant Circuit, Evacuating Refrigerant Circuit, Discharging Refrigerant Gas Analysis, Performing Refrigerant Circuit, Flushing With Compressed Air Or Nitrogen Refrigerant Circuit, Cleaning Process Refrigerant Circuit, Cleaning Refrigerant Circuit, Finding Leaks Using Electronic Leak Detector Refrigerant Temperature Sensor Refrigerant Circuit Connections With Valve For Switches Refrigerant Circuit Pipes And Hoses Refrigerant Line With Inner Heat Exchanger Refrigerant Shut-Off Valves Refrigerant Circuit Layout And Function Refrigerant Circuit Components, Replacing Refrigerant R134a Vapor Pressure Table . The expansion valve for the evaporator in the heater and A/C unit is faulty. Refer to Refrigerant Circuit Refrigerant Circuit (R1234yf) Refrigerant Lines, Disconnecting And Connecting At A/C Compressor Refrigerant Circuit With Ignition Switched On, Checking Pressure Refrigerant Circuit Pressures And Temperatures Refrigerant Circuit, Cleaning Refrigerant, Filling In Reservoir Refrigerant Circuit, Charging Refrigerant Circuit, Evacuating Refrigerant Circuit, Discharging Refrigerant Gas Analysis, Performing Refrigerant Circuit, Flushing With Compressed Air Or Nitrogen Refrigerant Circuit, Cleaning Process Refrigerant Circuit, Cleaning Refrigerant Circuit, Finding Leaks Using Electronic Leak Detector Refrigerant Temperature Sensor Refrigerant Circuit Connections With Valve For Switches Refrigerant Circuit Pipes And Hoses Refrigerant Line With Inner Heat Exchanger Refrigerant Shut-Off Valves Refrigerant Circuit Layout And Function Refrigerant Circuit Components, Replacing Refrigerant R134a Vapor Pressure Table . A refrigerant shut-off valve is faulty (closed). Use the Vehicle Diagnostic Tester in the "Guided Fault Finding" function for the A/C system and the battery regulation. Refer to Refrigerant Circuit Refrigerant Circuit (R1234yf) Refrigerant Lines, Disconnecting And Connecting At A/C Compressor Refrigerant Circuit With Ignition Switched On, Checking Pressure Refrigerant Circuit Pressures And Temperatures Refrigerant Circuit, Cleaning Refrigerant, Filling In Reservoir Refrigerant Circuit, Charging Refrigerant Circuit, Evacuating Refrigerant Circuit, Discharging Refrigerant Gas Analysis, Performing Refrigerant Circuit, Flushing With Compressed Air Or Nitrogen Refrigerant Circuit, Cleaning Process Refrigerant Circuit, Cleaning Refrigerant Circuit, Finding Leaks Using Electronic Leak Detector Refrigerant Temperature Sensor Refrigerant Circuit Connections With Valve For Switches Refrigerant Circuit Pipes And Hoses Refrigerant Line With Inner Heat Exchanger Refrigerant Shut-Off Valves Refrigerant Circuit Layout And Function Refrigerant Circuit Components, Replacing Refrigerant R134a Vapor Pressure Table . -- If equipped check the function of the installed shut-off valve. Refer to Refrigerant Circuit Refrigerant Circuit (R1234yf) Refrigerant Lines, Disconnecting And Connecting At A/C Compressor Refrigerant Circuit With Ignition Switched On, Checking Pressure Refrigerant Circuit Pressures And Temperatures Refrigerant Circuit, Cleaning Refrigerant, Filling In Reservoir Refrigerant Circuit, Charging Refrigerant Circuit, Evacuating Refrigerant Circuit, Discharging Refrigerant Gas Analysis, Performing Refrigerant Circuit, Flushing With Compressed Air Or Nitrogen Refrigerant Circuit, Cleaning Process Refrigerant Circuit, Cleaning Refrigerant Circuit, Finding Leaks Using Electronic Leak Detector Refrigerant Temperature Sensor Refrigerant Circuit Connections With Valve For Switches Refrigerant Circuit Pipes And Hoses Refrigerant Line With Inner Heat Exchanger Refrigerant Shut-Off Valves Refrigerant Circuit Layout And Function Refrigerant Circuit Components, Replacing Refrigerant R134a Vapor Pressure Table .-- Replace the expansion valve for the evaporator in the heater and A/C unit. Refer to Refrigerant Circuit Refrigerant Circuit (R1234yf) Refrigerant Lines, Disconnecting And Connecting At A/C Compressor Refrigerant Circuit With Ignition Switched On, Checking Pressure Refrigerant Circuit Pressures And Temperatures Refrigerant Circuit, Cleaning Refrigerant, Filling In Reservoir Refrigerant Circuit, Charging Refrigerant Circuit, Evacuating Refrigerant Circuit, Discharging Refrigerant Gas Analysis, Performing Refrigerant Circuit, Flushing With Compressed Air Or Nitrogen Refrigerant Circuit, Cleaning Process Refrigerant Circuit, Cleaning Refrigerant Circuit, Finding Leaks Using Electronic Leak Detector Refrigerant Temperature Sensor Refrigerant Circuit Connections With Valve For Switches Refrigerant Circuit Pipes And Hoses Refrigerant Line With Inner Heat Exchanger Refrigerant Shut-Off Valves Refrigerant Circuit Layout And Function Refrigerant Circuit Components, Replacing Refrigerant R134a Vapor Pressure Table .
Final Procedures
-- Charge the refrigerant circuit. Refer to REFRIGERANT CIRCUIT, CHARGING .-- Repeat the test. Refer to ELECTRICALLY-DRIVEN A/C COMPRESSOR, CHECKING PRESSURE WITH A/C SYSTEM SWITCHED ON .

NOTE:

Pay attention to previous notes.

Possible Deviation from Specified Value During the Pressure Test
The required cooling output is not attained in the heater and A/C unit evaporator (and in the evaporator for battery cooling). The required cooling output is only not attained at the heater and A/C unit evaporator (the cooling output on the evaporator for the cooling output is OK). The high pressure only falls slightly (via the pressure with the A/C compressor stopped) or corresponds to the specified value. Low pressure quickly drops to target value or lower.
Possible causes for the deviation from specified value and their solutions
There is too little refrigerant in the refrigerant circuit. -- Extract refrigerant from the refrigerant circuit. Refer to REFRIGERANT CIRCUIT, DISCHARGING .-- If the extracted refrigerant quantity is substantially smaller (more than 100g (3.5 oz)) than the specified capacity, there is too much refrigerant in the refrigerant circuit. Refer to LEAKS, FINDING and TECHNICAL DATA .-- If the extracted refrigerant quantity corresponds to the capacity or is only slightly smaller (maximum (3.5 oz)). Refer to TECHNICAL DATA . Check the expansion valve and shut-off valve for function. Refer to Refrigerant Circuit Refrigerant Circuit (R1234yf) Refrigerant Lines, Disconnecting And Connecting At A/C Compressor Refrigerant Circuit With Ignition Switched On, Checking Pressure Refrigerant Circuit Pressures And Temperatures Refrigerant Circuit, Cleaning Refrigerant, Filling In Reservoir Refrigerant Circuit, Charging Refrigerant Circuit, Evacuating Refrigerant Circuit, Discharging Refrigerant Gas Analysis, Performing Refrigerant Circuit, Flushing With Compressed Air Or Nitrogen Refrigerant Circuit, Cleaning Process Refrigerant Circuit, Cleaning Refrigerant Circuit, Finding Leaks Using Electronic Leak Detector Refrigerant Temperature Sensor Refrigerant Circuit Connections With Valve For Switches Refrigerant Circuit Pipes And Hoses Refrigerant Line With Inner Heat Exchanger Refrigerant Shut-Off Valves Refrigerant Circuit Layout And Function Refrigerant Circuit Components, Replacing Refrigerant R134a Vapor Pressure Table . The expansion valve for the evaporator in the heater and A/C unit is faulty. Refer to Refrigerant Circuit Refrigerant Circuit (R1234yf) Refrigerant Lines, Disconnecting And Connecting At A/C Compressor Refrigerant Circuit With Ignition Switched On, Checking Pressure Refrigerant Circuit Pressures And Temperatures Refrigerant Circuit, Cleaning Refrigerant, Filling In Reservoir Refrigerant Circuit, Charging Refrigerant Circuit, Evacuating Refrigerant Circuit, Discharging Refrigerant Gas Analysis, Performing Refrigerant Circuit, Flushing With Compressed Air Or Nitrogen Refrigerant Circuit, Cleaning Process Refrigerant Circuit, Cleaning Refrigerant Circuit, Finding Leaks Using Electronic Leak Detector Refrigerant Temperature Sensor Refrigerant Circuit Connections With Valve For Switches Refrigerant Circuit Pipes And Hoses Refrigerant Line With Inner Heat Exchanger Refrigerant Shut-Off Valves Refrigerant Circuit Layout And Function Refrigerant Circuit Components, Replacing Refrigerant R134a Vapor Pressure Table . A refrigerant shut-off valve is faulty (closed), check the function. Use the Vehicle Diagnostic Tester in the "Guided Fault Finding" function for the A/C system and the battery regulation. Refer to Refrigerant Circuit Refrigerant Circuit (R1234yf) Refrigerant Lines, Disconnecting And Connecting At A/C Compressor Refrigerant Circuit With Ignition Switched On, Checking Pressure Refrigerant Circuit Pressures And Temperatures Refrigerant Circuit, Cleaning Refrigerant, Filling In Reservoir Refrigerant Circuit, Charging Refrigerant Circuit, Evacuating Refrigerant Circuit, Discharging Refrigerant Gas Analysis, Performing Refrigerant Circuit, Flushing With Compressed Air Or Nitrogen Refrigerant Circuit, Cleaning Process Refrigerant Circuit, Cleaning Refrigerant Circuit, Finding Leaks Using Electronic Leak Detector Refrigerant Temperature Sensor Refrigerant Circuit Connections With Valve For Switches Refrigerant Circuit Pipes And Hoses Refrigerant Line With Inner Heat Exchanger Refrigerant Shut-Off Valves Refrigerant Circuit Layout And Function Refrigerant Circuit Components, Replacing Refrigerant R134a Vapor Pressure Table for replacing. -- If equipped check the function of the installed shut-off valve. Refer to Refrigerant Circuit Refrigerant Circuit (R1234yf) Refrigerant Lines, Disconnecting And Connecting At A/C Compressor Refrigerant Circuit With Ignition Switched On, Checking Pressure Refrigerant Circuit Pressures And Temperatures Refrigerant Circuit, Cleaning Refrigerant, Filling In Reservoir Refrigerant Circuit, Charging Refrigerant Circuit, Evacuating Refrigerant Circuit, Discharging Refrigerant Gas Analysis, Performing Refrigerant Circuit, Flushing With Compressed Air Or Nitrogen Refrigerant Circuit, Cleaning Process Refrigerant Circuit, Cleaning Refrigerant Circuit, Finding Leaks Using Electronic Leak Detector Refrigerant Temperature Sensor Refrigerant Circuit Connections With Valve For Switches Refrigerant Circuit Pipes And Hoses Refrigerant Line With Inner Heat Exchanger Refrigerant Shut-Off Valves Refrigerant Circuit Layout And Function Refrigerant Circuit Components, Replacing Refrigerant R134a Vapor Pressure Table .-- Replace the expansion valve for the evaporator in the heater and A/C unit. Refer to Refrigerant Circuit Refrigerant Circuit (R1234yf) Refrigerant Lines, Disconnecting And Connecting At A/C Compressor Refrigerant Circuit With Ignition Switched On, Checking Pressure Refrigerant Circuit Pressures And Temperatures Refrigerant Circuit, Cleaning Refrigerant, Filling In Reservoir Refrigerant Circuit, Charging Refrigerant Circuit, Evacuating Refrigerant Circuit, Discharging Refrigerant Gas Analysis, Performing Refrigerant Circuit, Flushing With Compressed Air Or Nitrogen Refrigerant Circuit, Cleaning Process Refrigerant Circuit, Cleaning Refrigerant Circuit, Finding Leaks Using Electronic Leak Detector Refrigerant Temperature Sensor Refrigerant Circuit Connections With Valve For Switches Refrigerant Circuit Pipes And Hoses Refrigerant Line With Inner Heat Exchanger Refrigerant Shut-Off Valves Refrigerant Circuit Layout And Function Refrigerant Circuit Components, Replacing Refrigerant R134a Vapor Pressure Table . Constriction or blockage in the refrigerant circuit (for example in the refrigerant line between the "low pressure side" service connection and the A/C compressor). Refer to Refrigerant Circuit Refrigerant Circuit (R1234yf) Refrigerant Lines, Disconnecting And Connecting At A/C Compressor Refrigerant Circuit With Ignition Switched On, Checking Pressure Refrigerant Circuit Pressures And Temperatures Refrigerant Circuit, Cleaning Refrigerant, Filling In Reservoir Refrigerant Circuit, Charging Refrigerant Circuit, Evacuating Refrigerant Circuit, Discharging Refrigerant Gas Analysis, Performing Refrigerant Circuit, Flushing With Compressed Air Or Nitrogen Refrigerant Circuit, Cleaning Process Refrigerant Circuit, Cleaning Refrigerant Circuit, Finding Leaks Using Electronic Leak Detector Refrigerant Temperature Sensor Refrigerant Circuit Connections With Valve For Switches Refrigerant Circuit Pipes And Hoses Refrigerant Line With Inner Heat Exchanger Refrigerant Shut-Off Valves Refrigerant Circuit Layout And Function Refrigerant Circuit Components, Replacing Refrigerant R134a Vapor Pressure Table . Activation of the A/C compressor is malfunctioning. Use the Vehicle Diagnostic Tester in the "Guided Fault Finding" function for the A/C system and the battery regulation. -- Check the activation and function of the A/C compressor and service. Use the Vehicle Diagnostic Tester in the "Guided Fault Finding" function of the A/C system and the battery regulation. If not error can be determined run hand over refrigerant circuit to check for differences in temperature. Refer to Refrigerant Circuit Refrigerant Circuit (R1234yf) Refrigerant Lines, Disconnecting And Connecting At A/C Compressor Refrigerant Circuit With Ignition Switched On, Checking Pressure Refrigerant Circuit Pressures And Temperatures Refrigerant Circuit, Cleaning Refrigerant, Filling In Reservoir Refrigerant Circuit, Charging Refrigerant Circuit, Evacuating Refrigerant Circuit, Discharging Refrigerant Gas Analysis, Performing Refrigerant Circuit, Flushing With Compressed Air Or Nitrogen Refrigerant Circuit, Cleaning Process Refrigerant Circuit, Cleaning Refrigerant Circuit, Finding Leaks Using Electronic Leak Detector Refrigerant Temperature Sensor Refrigerant Circuit Connections With Valve For Switches Refrigerant Circuit Pipes And Hoses Refrigerant Line With Inner Heat Exchanger Refrigerant Shut-Off Valves Refrigerant Circuit Layout And Function Refrigerant Circuit Components, Replacing Refrigerant R134a Vapor Pressure Table .-- If difference in temperature is found at one component: If the hose or pipe is kinked or constricted, replace this component and replace a faulty expansion valve. Refer to Refrigerant Circuit Refrigerant Circuit (R1234yf) Refrigerant Lines, Disconnecting And Connecting At A/C Compressor Refrigerant Circuit With Ignition Switched On, Checking Pressure Refrigerant Circuit Pressures And Temperatures Refrigerant Circuit, Cleaning Refrigerant, Filling In Reservoir Refrigerant Circuit, Charging Refrigerant Circuit, Evacuating Refrigerant Circuit, Discharging Refrigerant Gas Analysis, Performing Refrigerant Circuit, Flushing With Compressed Air Or Nitrogen Refrigerant Circuit, Cleaning Process Refrigerant Circuit, Cleaning Refrigerant Circuit, Finding Leaks Using Electronic Leak Detector Refrigerant Temperature Sensor Refrigerant Circuit Connections With Valve For Switches Refrigerant Circuit Pipes And Hoses Refrigerant Line With Inner Heat Exchanger Refrigerant Shut-Off Valves Refrigerant Circuit Layout And Function Refrigerant Circuit Components, Replacing Refrigerant R134a Vapor Pressure Table . If there is a blockage clean the refrigerant circuit (flush with refrigerant R1234yf). Refer to REFRIGERANT CIRCUIT, CLEANING .-- If there is a blockage clean the refrigerant circuit (flush with refrigerant R1234yf). Refer to REFRIGERANT CIRCUIT, CLEANING . Replace the expansion valve for the evaporator in the A/C unit (and for the evaporator for battery cooling) as well as the desiccant bag/dryer cartridge (or receiver/receiver/dryer). Refer to COMPONENTS, REPLACING and Refrigerant Circuit Refrigerant Circuit (R1234yf) Refrigerant Lines, Disconnecting And Connecting At A/C Compressor Refrigerant Circuit With Ignition Switched On, Checking Pressure Refrigerant Circuit Pressures And Temperatures Refrigerant Circuit, Cleaning Refrigerant, Filling In Reservoir Refrigerant Circuit, Charging Refrigerant Circuit, Evacuating Refrigerant Circuit, Discharging Refrigerant Gas Analysis, Performing Refrigerant Circuit, Flushing With Compressed Air Or Nitrogen Refrigerant Circuit, Cleaning Process Refrigerant Circuit, Cleaning Refrigerant Circuit, Finding Leaks Using Electronic Leak Detector Refrigerant Temperature Sensor Refrigerant Circuit Connections With Valve For Switches Refrigerant Circuit Pipes And Hoses Refrigerant Line With Inner Heat Exchanger Refrigerant Shut-Off Valves Refrigerant Circuit Layout And Function Refrigerant Circuit Components, Replacing Refrigerant R134a Vapor Pressure Table .
Final Procedures
-- Charge the refrigerant circuit. Refer to REFRIGERANT CIRCUIT, CHARGING .-- Repeat the test. Refer to ELECTRICALLY-DRIVEN A/C COMPRESSOR, CHECKING PRESSURE WITH A/C SYSTEM SWITCHED ON .

NOTE:

Pay attention to the previous notes.

Possible Deviation from Specified Value during the Pressure Test
The required cooling output is not attained in the heater and A/C unit evaporator (and in the evaporator for battery cooling). The high pressure increases above specification Low pressure quickly drops to specified value or lower.
Possible causes for the deviation from specified value and their solutions
A/C compressor activation or functionality malfunctioning. Constriction or obstruction in refrigerant circuit Expansion valve malfunctioning -- Check the activation and function of the A/C compressor and service. Use the Vehicle Diagnostic Tester in the "Guided Fault Finding" function of the A/C system and the battery regulation. If not error can be determined run hand over refrigerant circuit to check for differences in temperature. Refer to Refrigerant Circuit Refrigerant Circuit (R1234yf) Refrigerant Lines, Disconnecting And Connecting At A/C Compressor Refrigerant Circuit With Ignition Switched On, Checking Pressure Refrigerant Circuit Pressures And Temperatures Refrigerant Circuit, Cleaning Refrigerant, Filling In Reservoir Refrigerant Circuit, Charging Refrigerant Circuit, Evacuating Refrigerant Circuit, Discharging Refrigerant Gas Analysis, Performing Refrigerant Circuit, Flushing With Compressed Air Or Nitrogen Refrigerant Circuit, Cleaning Process Refrigerant Circuit, Cleaning Refrigerant Circuit, Finding Leaks Using Electronic Leak Detector Refrigerant Temperature Sensor Refrigerant Circuit Connections With Valve For Switches Refrigerant Circuit Pipes And Hoses Refrigerant Line With Inner Heat Exchanger Refrigerant Shut-Off Valves Refrigerant Circuit Layout And Function Refrigerant Circuit Components, Replacing Refrigerant R134a Vapor Pressure Table .-- If difference in temperature is found at one component: If the hose or pipe is kinked or constricted, replace this component and replace a faulty expansion valve. Refer to Refrigerant Circuit Refrigerant Circuit (R1234yf) Refrigerant Lines, Disconnecting And Connecting At A/C Compressor Refrigerant Circuit With Ignition Switched On, Checking Pressure Refrigerant Circuit Pressures And Temperatures Refrigerant Circuit, Cleaning Refrigerant, Filling In Reservoir Refrigerant Circuit, Charging Refrigerant Circuit, Evacuating Refrigerant Circuit, Discharging Refrigerant Gas Analysis, Performing Refrigerant Circuit, Flushing With Compressed Air Or Nitrogen Refrigerant Circuit, Cleaning Process Refrigerant Circuit, Cleaning Refrigerant Circuit, Finding Leaks Using Electronic Leak Detector Refrigerant Temperature Sensor Refrigerant Circuit Connections With Valve For Switches Refrigerant Circuit Pipes And Hoses Refrigerant Line With Inner Heat Exchanger Refrigerant Shut-Off Valves Refrigerant Circuit Layout And Function Refrigerant Circuit Components, Replacing Refrigerant R134a Vapor Pressure Table .-- If there is a blockage clean the refrigerant circuit (flush with refrigerant R1234yf). Refer to REFRIGERANT CIRCUIT, CLEANING . Replace the expansion valve for the evaporator in the A/C unit (and for the evaporator for battery cooling) as well as the desiccant bag/dryer cartridge (or receiver/receiver/dryer). Refer to COMPONENTS, REPLACING and Refrigerant Circuit Refrigerant Circuit (R1234yf) Refrigerant Lines, Disconnecting And Connecting At A/C Compressor Refrigerant Circuit With Ignition Switched On, Checking Pressure Refrigerant Circuit Pressures And Temperatures Refrigerant Circuit, Cleaning Refrigerant, Filling In Reservoir Refrigerant Circuit, Charging Refrigerant Circuit, Evacuating Refrigerant Circuit, Discharging Refrigerant Gas Analysis, Performing Refrigerant Circuit, Flushing With Compressed Air Or Nitrogen Refrigerant Circuit, Cleaning Process Refrigerant Circuit, Cleaning Refrigerant Circuit, Finding Leaks Using Electronic Leak Detector Refrigerant Temperature Sensor Refrigerant Circuit Connections With Valve For Switches Refrigerant Circuit Pipes And Hoses Refrigerant Line With Inner Heat Exchanger Refrigerant Shut-Off Valves Refrigerant Circuit Layout And Function Refrigerant Circuit Components, Replacing Refrigerant R134a Vapor Pressure Table . There is too little refrigerant in the refrigerant circuit. -- Extract refrigerant from the refrigerant circuit. Refer to REFRIGERANT CIRCUIT, DISCHARGING .-- If the extracted refrigerant quantity is significantly less than the specified capacity (more that 100g (3.5 oz)) and look for leaks and correct. Refer to LEAKS, FINDING . and TECHNICAL DATA .-- If the extracted refrigerant quantity corresponds to the capacity or is only slightly smaller (maximum 100g (3.5 oz)) and check the refrigerant shut-off valve for function. Refer to TECHNICAL DATA and Refrigerant Circuit Refrigerant Circuit (R1234yf) Refrigerant Lines, Disconnecting And Connecting At A/C Compressor Refrigerant Circuit With Ignition Switched On, Checking Pressure Refrigerant Circuit Pressures And Temperatures Refrigerant Circuit, Cleaning Refrigerant, Filling In Reservoir Refrigerant Circuit, Charging Refrigerant Circuit, Evacuating Refrigerant Circuit, Discharging Refrigerant Gas Analysis, Performing Refrigerant Circuit, Flushing With Compressed Air Or Nitrogen Refrigerant Circuit, Cleaning Process Refrigerant Circuit, Cleaning Refrigerant Circuit, Finding Leaks Using Electronic Leak Detector Refrigerant Temperature Sensor Refrigerant Circuit Connections With Valve For Switches Refrigerant Circuit Pipes And Hoses Refrigerant Line With Inner Heat Exchanger Refrigerant Shut-Off Valves Refrigerant Circuit Layout And Function Refrigerant Circuit Components, Replacing Refrigerant R134a Vapor Pressure Table .
Final Procedures
-- Charge the refrigerant circuit. Refer to REFRIGERANT CIRCUIT, CHARGING .-- Repeat the test. Refer to ELECTRICALLY-DRIVEN A/C COMPRESSOR, CHECKING PRESSURE WITH A/C SYSTEM SWITCHED ON .

NOTE:

If the A/C system function when repeating the test is not OK, replace the expansion valve and desiccant bag/dryer cartridge (or receiver/receiver/dryer) and if equipped refrigerant shut-off valve. Refer to

With this malfunction, evaporator may ice up although the quantity of refrigerant in circuit is OK.

If the expansion valve in the heater and A/C unit evaporator or the refrigerant shut-off valve 1 is malfunctioning (permanently closed or does not open sufficiently), the A/C compressor is actuated to maximum output and the low pressure drops to specification or below (compressor draws off refrigerant from low-pressure side). As the refrigerant cannot flow via the expansion valve (the refrigerant shut-off valve), if the cooling output is not attained, high pressure may also not increase or only increase slightly due to the absence of energy. Use the Vehicle Diagnostic Tester in the "Guided Fault Finding" function for the A/C system and the battery regulation. Refer to

If the expansion valve on the evaporator for the battery cooling is faulty (or if the functionality or activation of the refrigerant shut-off valve 2 is malfunctioning), constantly closed or does not open enough, then the A/C compressor is likewise activated with the maximum output (the required temperatures in the battery cooling module are not attained). The pressure on the low pressure side only falls to the specified value or lower when there is no cooling output requested at the same time in the heater and A/C unit (the refrigerant shut-off valve 1 is activated and is closed). The A/C compressor extracts the refrigerant from the low pressure side from both evaporators). Since, however, no refrigerant can flow over the expansion valve in the A/C unit (the refrigerant shut-off valve 1) and the cooling output for the battery cooling is not attained (there is a malfunction in the area of the battery cooling), the electrical A/C compressor will be activated with a higher speed. Since, however, no refrigerant can flow through, the pressure on the low pressure side falls below the specified value. In addition, the high pressure may never or only slightly increase, due to the absence of energy. Use the Vehicle Diagnostic Tester in the "Guided Fault Finding" function for the A/C system and the battery regulation. Refer to

Since the evaporator output for the battery cooling is noticeably smaller than the evaporator output in the A/C unit, the required specified temperature may still be reached for the battery cooling with too little refrigerant in the circuit, but the specified temperature in the heater and A/C unit evaporator will no longer be attainable (even though the A/C compressor is activated with an increased speed).

If there is too much refrigerant oil in the circuit, the A/C compressor must be emptied and the desiccant bag (the dryer cartridge) or the receiver/receiver/dryer must be replaced. After cleaning (flushing with refrigerant R1234yf) and fill the refrigerant circuit with the correct quantity of refrigerant oil. Refer to REFRIGERANT CIRCUIT, CLEANING , TECHNICAL DATA and

Refer to ELECTRICALLY-DRIVEN A/C COMPRESSOR, CHECKING PRESSURE WITH A/C SYSTEM SWITCHED ON If for this complaint a malfunction is determined in the diagnostic, check the refrigerant circuit for a constriction or blockage (a constriction or a blockage in the refrigerant circuit can also lead to these complaints). If nothing is determined here, clean the refrigerant circuit (flush with refrigerant R1234yf). for further information.

Possible Deviation from Specified Value during the Pressure Test
The required cooling output is only not attained at the evaporator for the battery cooling module components (the cooling output at the heater and A/C unit evaporator is OK). The high pressure corresponds to the specified value or increases only slightly (above pressure with engine stopped). Low pressure drops to specified value or lower.
Possible causes for the deviation from specified value and their solutions
Check the activation and function of the refrigerant shut-off valve 2, an adjustment motor, the blower or a temperature sensor in or on a battery cooling module is faulty service if necessary. use the Vehicle Diagnostic Tester in the "Guided Fault Finding" function of the A/C system and the battery regulation. Refer to Refrigerant Circuit Refrigerant Circuit (R1234yf) Refrigerant Lines, Disconnecting And Connecting At A/C Compressor Refrigerant Circuit With Ignition Switched On, Checking Pressure Refrigerant Circuit Pressures And Temperatures Refrigerant Circuit, Cleaning Refrigerant, Filling In Reservoir Refrigerant Circuit, Charging Refrigerant Circuit, Evacuating Refrigerant Circuit, Discharging Refrigerant Gas Analysis, Performing Refrigerant Circuit, Flushing With Compressed Air Or Nitrogen Refrigerant Circuit, Cleaning Process Refrigerant Circuit, Cleaning Refrigerant Circuit, Finding Leaks Using Electronic Leak Detector Refrigerant Temperature Sensor Refrigerant Circuit Connections With Valve For Switches Refrigerant Circuit Pipes And Hoses Refrigerant Line With Inner Heat Exchanger Refrigerant Shut-Off Valves Refrigerant Circuit Layout And Function Refrigerant Circuit Components, Replacing Refrigerant R134a Vapor Pressure Table . If the expansion valve for the expansion valve in the battery cooling module is faulty. -- Replace the expansion valve for the evaporator for battery cooling. Refer to Refrigerant Circuit Refrigerant Circuit (R1234yf) Refrigerant Lines, Disconnecting And Connecting At A/C Compressor Refrigerant Circuit With Ignition Switched On, Checking Pressure Refrigerant Circuit Pressures And Temperatures Refrigerant Circuit, Cleaning Refrigerant, Filling In Reservoir Refrigerant Circuit, Charging Refrigerant Circuit, Evacuating Refrigerant Circuit, Discharging Refrigerant Gas Analysis, Performing Refrigerant Circuit, Flushing With Compressed Air Or Nitrogen Refrigerant Circuit, Cleaning Process Refrigerant Circuit, Cleaning Refrigerant Circuit, Finding Leaks Using Electronic Leak Detector Refrigerant Temperature Sensor Refrigerant Circuit Connections With Valve For Switches Refrigerant Circuit Pipes And Hoses Refrigerant Line With Inner Heat Exchanger Refrigerant Shut-Off Valves Refrigerant Circuit Layout And Function Refrigerant Circuit Components, Replacing Refrigerant R134a Vapor Pressure Table .-- If no malfunction can be determined, check the function and activation of the components for battery cooling. Use the Vehicle Diagnostic Tester in the "Guided Fault Finding" function for the A/C system and check the battery regulation and refrigerant lines. Constriction or blockage in the refrigerant line either to or from the expansion valve on the evaporator for battery cooling. -- If there is a blockage clean the refrigerant circuit (flush with refrigerant R1234yf). Refer to REFRIGERANT CIRCUIT, CLEANING . Replace the expansion valve for the evaporator in the A/C unit (and for the evaporator for battery cooling) as well as the desiccant bag/dryer cartridge (or receiver/receiver/dryer). Refer to COMPONENTS, REPLACING and Refrigerant Circuit Refrigerant Circuit (R1234yf) Refrigerant Lines, Disconnecting And Connecting At A/C Compressor Refrigerant Circuit With Ignition Switched On, Checking Pressure Refrigerant Circuit Pressures And Temperatures Refrigerant Circuit, Cleaning Refrigerant, Filling In Reservoir Refrigerant Circuit, Charging Refrigerant Circuit, Evacuating Refrigerant Circuit, Discharging Refrigerant Gas Analysis, Performing Refrigerant Circuit, Flushing With Compressed Air Or Nitrogen Refrigerant Circuit, Cleaning Process Refrigerant Circuit, Cleaning Refrigerant Circuit, Finding Leaks Using Electronic Leak Detector Refrigerant Temperature Sensor Refrigerant Circuit Connections With Valve For Switches Refrigerant Circuit Pipes And Hoses Refrigerant Line With Inner Heat Exchanger Refrigerant Shut-Off Valves Refrigerant Circuit Layout And Function Refrigerant Circuit Components, Replacing Refrigerant R134a Vapor Pressure Table .-- If the hose or pipe is kinked or constricted, replace this component. Refer to Refrigerant Circuit Refrigerant Circuit (R1234yf) Refrigerant Lines, Disconnecting And Connecting At A/C Compressor Refrigerant Circuit With Ignition Switched On, Checking Pressure Refrigerant Circuit Pressures And Temperatures Refrigerant Circuit, Cleaning Refrigerant, Filling In Reservoir Refrigerant Circuit, Charging Refrigerant Circuit, Evacuating Refrigerant Circuit, Discharging Refrigerant Gas Analysis, Performing Refrigerant Circuit, Flushing With Compressed Air Or Nitrogen Refrigerant Circuit, Cleaning Process Refrigerant Circuit, Cleaning Refrigerant Circuit, Finding Leaks Using Electronic Leak Detector Refrigerant Temperature Sensor Refrigerant Circuit Connections With Valve For Switches Refrigerant Circuit Pipes And Hoses Refrigerant Line With Inner Heat Exchanger Refrigerant Shut-Off Valves Refrigerant Circuit Layout And Function Refrigerant Circuit Components, Replacing Refrigerant R134a Vapor Pressure Table . Not enough refrigerant in refrigerant circuit Extract refrigerant from the refrigerant circuit. Refer to REFRIGERANT CIRCUIT, DISCHARGING . If the extracted refrigerant quantity is significantly less than the specified capacity (more that 100g (3.5 oz)). Refer to TECHNICAL DATA , and look for leaks and correct. Refer to LEAKS, FINDING . If the extracted refrigerant quantity corresponds to the capacity or is only slightly smaller (maximum 100g (3.5 oz)). Refer to TECHNICAL DATA , refrigerant shut-off valve 1. Use the Vehicle Diagnostic Tester in the "Guided Fault Finding" function for the A/C system function and the battery regulation. Refer to Refrigerant Circuit Refrigerant Circuit (R1234yf) Refrigerant Lines, Disconnecting And Connecting At A/C Compressor Refrigerant Circuit With Ignition Switched On, Checking Pressure Refrigerant Circuit Pressures And Temperatures Refrigerant Circuit, Cleaning Refrigerant, Filling In Reservoir Refrigerant Circuit, Charging Refrigerant Circuit, Evacuating Refrigerant Circuit, Discharging Refrigerant Gas Analysis, Performing Refrigerant Circuit, Flushing With Compressed Air Or Nitrogen Refrigerant Circuit, Cleaning Process Refrigerant Circuit, Cleaning Refrigerant Circuit, Finding Leaks Using Electronic Leak Detector Refrigerant Temperature Sensor Refrigerant Circuit Connections With Valve For Switches Refrigerant Circuit Pipes And Hoses Refrigerant Line With Inner Heat Exchanger Refrigerant Shut-Off Valves Refrigerant Circuit Layout And Function Refrigerant Circuit Components, Replacing Refrigerant R134a Vapor Pressure Table .
Final Procedures
-- Charge the refrigerant circuit. Refer to REFRIGERANT CIRCUIT, CHARGING .-- Repeat the test. Refer to ELECTRICALLY-DRIVEN A/C COMPRESSOR, CHECKING PRESSURE WITH A/C SYSTEM SWITCHED ON .

NOTE:

For cooling the Electric Vehicle Battery -A2- (hybrid battery) the refrigerant shut-off valve 1 is currently activated from a specific battery temperature for example from the battery regulation control module. If the A/C system driver is not already activated at this time, the Electrical A/C Compressor -V470- is activated via the A/C Compressor Control Module -J842- for example by the battery regulation control module. The temperature of the air (or the coolant) before and after the evaporator for battery cooling module is calculated by the respective control module (for example by the battery regulation control module). If at the same time it is determined that the cooling is not sufficient this is stored for example in the battery regulation control module. Use the Vehicle Diagnostic Tester in the "Guided Fault Finding" function of the A/C system and the battery regulation.

The temperature of the air (or the coolant) and the evaporator cooling output in the battery cooling module is determined via the installed temperature sensor (it currently cannot be measured using a thermometer while operating) and may only for this reason be checked using the Guided Fault Finding. Use the Vehicle Diagnostic Tester in the "Guided Fault Finding" function of the A/C System and the battery regulation.

Possible Deviation from Specified Value during the Pressure Test
The required cooling output is not attained in the heater and A/C unit evaporator (and in the evaporator for battery cooling). The high pressure does not increase or only increases slightly above pressure with engine stopped. The low pressure does not drop or drops only slightly.
Possible causes for the deviation from specified value and their solutions
No activation of the A/C compressor. Use the Vehicle Diagnostic Tester in the "Guided Fault Finding" function. If equipped, the refrigerant shut-off valve 1 is faulty (closed) -- Check the activation and function of the A/C compressor (and the refrigerant shut-off valve 1, the refrigerant shut-off valve 2). Use the Vehicle Diagnostic Tester in the "Guided Fault Finding" function of the A/C compressor and the battery regulation. If no malfunction can be determined replace the expansion valve on the evaporator in the heater and A/C unit. Refer to Refrigerant Circuit Refrigerant Circuit (R1234yf) Refrigerant Lines, Disconnecting And Connecting At A/C Compressor Refrigerant Circuit With Ignition Switched On, Checking Pressure Refrigerant Circuit Pressures And Temperatures Refrigerant Circuit, Cleaning Refrigerant, Filling In Reservoir Refrigerant Circuit, Charging Refrigerant Circuit, Evacuating Refrigerant Circuit, Discharging Refrigerant Gas Analysis, Performing Refrigerant Circuit, Flushing With Compressed Air Or Nitrogen Refrigerant Circuit, Cleaning Process Refrigerant Circuit, Cleaning Refrigerant Circuit, Finding Leaks Using Electronic Leak Detector Refrigerant Temperature Sensor Refrigerant Circuit Connections With Valve For Switches Refrigerant Circuit Pipes And Hoses Refrigerant Line With Inner Heat Exchanger Refrigerant Shut-Off Valves Refrigerant Circuit Layout And Function Refrigerant Circuit Components, Replacing Refrigerant R134a Vapor Pressure Table . Constriction or obstruction in refrigerant circuit (for example, inside the refrigerant line between the service connection "low pressure side" and the A/C compressor). -- If there is a blockage clean the refrigerant circuit (flush with refrigerant R1234yf). Refer to REFRIGERANT CIRCUIT, CLEANING . Replace the expansion valve for the evaporator in the A/C unit (and for the evaporator for battery cooling) as well as the desiccant bag/dryer cartridge (or receiver/receiver/dryer). Refer to COMPONENTS, REPLACING and Refrigerant Circuit Refrigerant Circuit (R1234yf) Refrigerant Lines, Disconnecting And Connecting At A/C Compressor Refrigerant Circuit With Ignition Switched On, Checking Pressure Refrigerant Circuit Pressures And Temperatures Refrigerant Circuit, Cleaning Refrigerant, Filling In Reservoir Refrigerant Circuit, Charging Refrigerant Circuit, Evacuating Refrigerant Circuit, Discharging Refrigerant Gas Analysis, Performing Refrigerant Circuit, Flushing With Compressed Air Or Nitrogen Refrigerant Circuit, Cleaning Process Refrigerant Circuit, Cleaning Refrigerant Circuit, Finding Leaks Using Electronic Leak Detector Refrigerant Temperature Sensor Refrigerant Circuit Connections With Valve For Switches Refrigerant Circuit Pipes And Hoses Refrigerant Line With Inner Heat Exchanger Refrigerant Shut-Off Valves Refrigerant Circuit Layout And Function Refrigerant Circuit Components, Replacing Refrigerant R134a Vapor Pressure Table .-- If the hose or pipe is kinked or constricted, replace this component. Refer to Refrigerant Circuit Refrigerant Circuit (R1234yf) Refrigerant Lines, Disconnecting And Connecting At A/C Compressor Refrigerant Circuit With Ignition Switched On, Checking Pressure Refrigerant Circuit Pressures And Temperatures Refrigerant Circuit, Cleaning Refrigerant, Filling In Reservoir Refrigerant Circuit, Charging Refrigerant Circuit, Evacuating Refrigerant Circuit, Discharging Refrigerant Gas Analysis, Performing Refrigerant Circuit, Flushing With Compressed Air Or Nitrogen Refrigerant Circuit, Cleaning Process Refrigerant Circuit, Cleaning Refrigerant Circuit, Finding Leaks Using Electronic Leak Detector Refrigerant Temperature Sensor Refrigerant Circuit Connections With Valve For Switches Refrigerant Circuit Pipes And Hoses Refrigerant Line With Inner Heat Exchanger Refrigerant Shut-Off Valves Refrigerant Circuit Layout And Function Refrigerant Circuit Components, Replacing Refrigerant R134a Vapor Pressure Table . A/C compressor faulty. -- Replace the A/C compressor. Refer to COMPONENTS, REPLACING and A/C Compressor A/C Compressor Regulator ValveN280 A/C Compressor Regulator Valve -N280-, Checking Switch-On Signal A/C Compressor Regulator ValveN280, Removing and Installing and Replacing A/C Service Station, Discharging A/C Service Station, Switching off and Disconnecting from Refrigerant Circuit A/C System, Operating after Charging A/C Service Station on Refrigerant Circuit, Connecting A/C Compressor, Replacing without the Need for Flushing Refrigerant Circuit A/C Pressure/Temperature Sensor A/C System, General Information .
Final Procedures
-- Charge the refrigerant circuit. Refer to REFRIGERANT CIRCUIT, CHARGING .-- Repeat the test. Refer to ELECTRICALLY-DRIVEN A/C COMPRESSOR, CHECKING PRESSURE WITH A/C SYSTEM SWITCHED ON .