A/C refrigerant system, checking pressures Audi A6 C5

A/C refrigerant system, checking pressures

Safety measures, see A/C SYSTEM, SAFETY PRECAUTIONS .

Before checking refrigerant system pressures, check A/C system cooling performance. See A/C SYSTEM COOLING PERFORMANCE, TESTING .

Use high pressure service valve for checking system pressures.

Test requirements

1. Condenser and radiator clean and free of obstructions (clean if necessary)
2. Drive belts for compressor and generator in good condition and properly tensioned
3. All air ducts, covers and seals OK and correctly installed
4. Check DTC memory using VAG 1551 scan tool and eliminate/repair any malfunctions indicated (not affecting A/C system)
5. All air distribution flaps reach end positions Engine at normal operating temperature
6. Evaporator housing and heater box do not leak air (draw in secondary air) at high fresh air blower speed
7. Outside (ambient) temperature must be between 15-45° C (59-113° F)
8. Engine running and system set to maximum cooling (AUTO operating mode with LO temperature setting selected)

1. Switch compressor on (warning light in ECON button does not light up)
2. Temperature selection LO (for driver and passenger side) If the compressor is activated (A/C clutch is switched on)

1. Fresh air blower -V2- runs
2. Coolant fan -Ml- runs (at least in 1st speed)
3. Air flow flap closes and fresh air/recirculated air flap opens (within 1 minute after starting vehicle)

Note. With fresh air/recirculated air flap open air flows out of outlets in the instrument panel even though the air flow flap is closed.