Possible Deviation from Specified Value During the Pressure Test (6 Of 11)

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
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 (3.5 oz)). 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 (3.5 oz)). 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 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 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 .

NOTE:

Pay attention to the notes to do so. Refer to Possible Deviation from Specified Value During the Pressure Test (1 Of 11) and Possible Deviation from Specified Value During the Pressure Test (5 Of 11) .