- 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 100 g). Refer to TECHNICAL DATA
(vehicle-specific service information), 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 100 g). Refer to TECHNICAL DATA
(vehicle-specific service information) and TECHNICAL DATA
. Check the Refrigerant Shut-Off Valve -- for function. Refer to the REFRIGERANT CIRCUIT
(vehicle-specific service information).
- The expansion valve for the evaporator in the heater and A/C unit is faulty. Refer to REFRIGERANT CIRCUIT
(vehicle-specific service information).
- 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 and refer to REFRIGERANT CIRCUIT
(vehicle-specific service information).
-- If equipped, check the function of the installed shut-off valve. Refer to REFRIGERANT CIRCUIT
(vehicle-specific service information).-- Replace the expansion valve for the evaporator in the heater and A/C unit. Refer to REFRIGERANT CIRCUIT
(vehicle-specific service information).
- 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 heater and A/C unit (and for the evaporator for battery cooling) as well as the desiccant bag/dryer cartridge (or reservoir/receiver/dryer). Refer to COMPONENTS, REPLACING
and REFRIGERANT CIRCUIT
(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 . |