Possible deviation from specified value during the pressure test (4 Of 12)
WARNING: This page is about a different car, the 2023 Audi SQ8, 2023 Audi RS Q8, and 2023 Audi Q8. 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
- Low pressure normal or too low (less than the specified value)
- The required cooling output is only not attained at the evaporator for cooling the high-voltage components (the cooling output at the front heater and A/C unit evaporator is OK).
|
| Possible causes for the deviation from specified value and their solutions |
- 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 of the pumps or one of the valves in the high-voltage system coolant circuit is faulty or does not function correctly. Refer to
Coolant 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
.
- Constriction of blockage in the refrigerant line to or from the expansion valve on the evaporator for cooling the high-voltage components.
-- 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 function and activation of the various valves 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).-- Check the function and activation of the components for cooling the high-voltage components. Refer to
Vehicle Diagnostic Tester in the Guided Fault Finding for the air conditioner, the A/C Compressor and the Battery Regulation.-- Depending on the result, service the activation or a faulty component (shut-off valve, expansion valve, coolant pump, coolant shut-off valve). Refer to
Refrigerant Circuit
(vehicle-specific service information) and
Refrigerant Circuit
(vehicle-specific service information).-- Check the refrigerant circuit lines, if they are kinked or constricted replace the hose or pipe of this component.-- If no malfunction can be determined 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 . |