- 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 100 g (3.5 oz)) than the specified capacity (vehicle-specific Service Information), 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
(vehicle-specific Service Information). Check the expansion valve and shut-off valve for function. Refer to
Air Conditioning (1 Of 3)
/ Air Conditioning (3 Of 3)
(vehicle-specific Service Information).
-- If equipped check the function of the installed shut-off valve. Refer to
Air Conditioning (1 Of 3)
/ Air Conditioning (3 Of 3)
(vehicle-specific Service Information).-- Replace the expansion valve for the evaporator in the heater and A/C unit. Refer to
Air Conditioning (1 Of 3)
/ Air Conditioning (3 Of 3)
(vehicle-specific Service Information).
- 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
Air Conditioning (1 Of 3)
/ Air Conditioning (3 Of 3)
(vehicle-specific Service Information).
- 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
Air Conditioning (1 Of 3)
/ Air Conditioning (3 Of 3)
(vehicle-specific Service Information).-- 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
Air Conditioning (1 Of 3)
/ Air Conditioning (3 Of 3)
(vehicle-specific Service Information). 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
Air Conditioning (1 Of 3)
/ Air Conditioning (3 Of 3)
(vehicle-specific Service 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 . |