Possible deviation from specified value during the pressure test (7 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 and low pressure normal at first, after some time high pressure increases above the specified value and the low pressure falls to the specified value or lower. The required cooling output is not or no longer attained in the 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
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 . 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). Moisture in refrigerant 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 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, 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 .

NOTE:

Read the supporting information. Refer to Possible deviation from specified value during the pressure test (1 Of 12) .