64 50... A/C performance test (R 134a)
Before A/C performance test, some conditions must be met:
- Provision of a BMW diagnostic system. Safeguard electrical system integrity by checking the fault memory (no faults in the fault memory).
- Provide a thermometer with separate gauge.
- Perform the test in a suitable workshop area with an ambient temperature between 20°C and 30°C.
Re 1:
Connect BMW diagnostic system to vehicle and display evaporator temperature.
Re 2:
Position a thermometer with a separate gauge approx. 5 cm below the roof liner at the height of the B-pillar. Lay gauge outwards out of vehicle interior.
Re 3:
Heating up the passenger compartment:
- A/C button is not activated when heating up.
- Close all windows and doors.
- Set air recirculation function.
- Select air distribution mode for footwell and defrosting.
- Maximum temperature setting
- Maximum blower speed
- Run engine at approx. 2000 RPM until operating temperature is reached, then idle speed.
Air-conditioning performance test:
Turn on A/C compressor at a vehicle interior temperature of 50°C.
After 3 to 4 minutes, the evaporator sensor temperature must be ≤ 15°C.
DRAW OFF AIR CONDITIONING if this temperature is not reached. Measure amount of refrigerant drawn off.
If drawn-off quantity does not correspond to SPECIFIED FILL QUANTITY : supplement refrigerant and repeat test.
If fill quantity is correct, continue troubleshooting by pressure measurement.
If necessary, then continue troubleshooting by pressure measurement.