Possible Deviation from Specified Value During the Pressure Test (10 Of 12)
WARNING: This page is about a different car, the 2022 Volkswagen ID.4 and 2021 Volkswagen ID.4. However, it is still accessible from the selected car via links, so may be relevant.
| Possible Deviation from Specified Value During the Pressure Test |
- High pressure normal or too high,
- Low pressure is too high,
- A/C compressor noise (particularly after switch-on),
- The required cooling output is not attained in the front heater and A/C unit evaporator and / or in the evaporator for cooling the high-voltage components.
|
| Possible causes for the deviation from specified value and their solutions |
- Activation of the A/C compressor is faulty. Use the Vehicle Diagnostic Tester
in the "Guided Fault Finding"
function.
- If one of the valves installed in the refrigerant circuit is faulty or does not work correctly. Refer to Refrigerant Circuit
(vehicle-specific Service Information).
- One in or on the removed refrigerant circuit pressure/temperature sensor or the temperature sensor sends incorrect values. Use the Vehicle Diagnostic Tester
in the "Guided Fault Finding"
function and Component Location Overview - A/C System
.
- Too much refrigerant in the circuit.
- Too much refrigerant oil in the circuit.
-- Check the measured values of the different pressure/temperature sensor and temperature sensor when operating the A/C system, and replace the components with incorrect measured values. Use the Vehicle Diagnostic Tester
in the "Guided Fault Finding"
function and refer to Component Location Overview - A/C System
.-- Check the activation and function of the A/C compressor and service using the Vehicle Diagnostic Tester
in the "Guided Fault Finding"
function.-- Check the function and activation of the various valves and pressure/temperature sensors installed in the refrigerant circuit via the pressure distribution in the refrigerant circuit. Use the Vehicle Diagnostic Tester
in the "Guided Fault Finding"
function and refer to Refrigerant Circuit
(vehicle-specific Service Information).-- If no malfunction can be determined, extract the refrigerant from the refrigerant circuit.
- If quantity of refrigerant extracted is substantially greater than specified capacity:
-- Fill the refrigerant circuit and repeat the test.
- If quantity of refrigerant extracted roughly corresponds to specified capacity:
-- Check the activation and function of the A/C compressor and the valves installed in the refrigerant circuit (shut-off valve and expansion valve). Use the Vehicle Diagnostic Tester
in the "Guided Fault Finding"
function.-- Depending on the result, service the activation or replace the faulty component (shut-off valve, expansion valve, or A/C compressor as well as the receiver/dryer/dryer). Refer to Refrigerant Circuit
(vehicle-specific Service Information).-- If no malfunction can be determined, there may be too much refrigerant oil in the circuit, clean the refrigerant circuit (flush with refrigerant R1234yf. Refer to 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 . |