LEMON Manuals: Even more car manuals for everyone
Home >> Audi >> 2020 >> SQ8 Premium Plus >> Repair and Diagnosis >> External Pages >> Different car >> Section 90 (Air Conditioning (Refrigerant R1234YF Tools & Testing Equipment)) >> 87 Air Conditioning >> Working With A/C Service Station >> Pressures, Checking >> Mechanically Driven A/C Compressor, Checking Pressure With A/C System Switched On >> Possible deviation from specified value during the pressure test (2 Of 9)

Possible deviation from specified value during the pressure test (2 Of 9)

WARNING: This page does not describe the selected car, but rather 6 other vehicles, including the 2024 Audi SQ5, 2024 Audi Q5 e, 2024 Audi Q5, 2023 Audi SQ5, and 2023 Audi Q5 e. 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 requested cooling output is not attained.
  • 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
  • There is too little refrigerant in the refrigerant circuit.
  • The expansion valve is faulty.
-- 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) less) (refer to Technical Data (vehicle-specific service information)), look for leaks and correct. Refer to LEAKS, FINDING .-- The extracted refrigerant quantity corresponds approximately to the specified capacity, replace expansion valve for the evaporator in the heater and A/C unit. Refer to Refrigerant Circuit (vehicle-specific service information).
Final Procedures
-- Charge the refrigerant circuit. Refer to REFRIGERANT CIRCUIT, CHARGING .-- Repeat the test. Refer to MECHANICALLY DRIVEN A/C COMPRESSOR, CHECKING PRESSURE WITH A/C SYSTEM SWITCHED ON .
NOTE:

Check the measured values of the Evaporator Vent Temperature Sensor -G263- and the activation of the A/C Compressor Regulator Valve A/C Compressor Regulator Valve -N280-. If the measured value of the Evaporator Vent Temperature Sensor Evaporator Vent Temperature Sensor -G263- malfunctions the evaporator can ice over or the cooling output is not reached. Use the Vehicle Diagnostic Tester in the "Guided Fault Finding" function of the A/C system.

If the A/C system function is not OK after repeating the test, for example after replacing expansion valve, clean the refrigerant circuit by flushing using the refrigerant R1234yf. Refer to REFRIGERANT CIRCUIT, CLEANING . Then replace the A/C compressor and reservoir/receiver/dryer (or dryer cartridge). Refer to Refrigerant Circuit (vehicle-specific service information).