64 50 ... Air Conditioner Test (R 134a)

64 50 ... A/C Performance Test (R 134a)

Before A/C performance test, some conditions must be met:
1. Provision of a BMW diagnostic system. Safeguard electrical system integrity by checking the fault memory (no faults in the fault memory).
2. Provide a thermometer with separate gauge.
3. 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 d 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.

NOTE:
Air conditioning with uncontrolled compressors only:
If necessary, then continue troubleshooting by pressure measurement.