64 50 ... A/C Performance Test (R134a)

64 50 ... A/C performance test (R134a)

Observe the following conditions prior to the A/C performance test:
1. Connect BMW diagnosis system. Check of the fault memory (no faults in the fault memory).
2. Attach a thermometer with separate display device to the head restraint and route the display device wiring out of the passenger compartment outward.
3. Perform the test in a suitable workshop area with an ambient temperature above 18 °C.
4. Vehicle temperature should be approximately the same as the ambient temperature in the workshop.
5. Engine must be at operating temperature.

Heat passenger compartment:
- "A/C button" is not activated during the heating process
- Close all windows and doors.
- Set air recirculation function.
- Select air distribution mode for footwell and defrosting.
- On vehicles with CID: In A/C menu (CID) in Air distribution index tab: select 100 % footwell for driver and front passenger and 100 % defrosting for driver (this applies here to driver and front passenger)
- Maximum temperature setting
- Maximum blower speed
- Start engine

Cool down passenger compartment:
Turn on air conditioning compressor with "A/C button" at a vehicle interior temperature of 45 °C (measured at the head restraint).

On vehicles with MAX AC button:
- Activation of MAX AC (= maximum cooling power)

On vehicles without MAX AC button:
- Set maximum cooling power by means of following steps:
- Setting minimum temperature
- Blower setting maximum
- Stratification maximum cold (4 blue bars)
- Only ventilation open
- Close remaining flaps (air outlet only from centre fresh air grille, left and right)

After 5 minutes measure both ventilation temperatures with a thermometer at the same time (fresh air grille centre, left and right). The measured temperature must be ≤ 16 °C and the difference between right and left may not be greater than 2 °C.

If one or both temperature specifications is not reached drain off heating and air conditioning system. Measure amount of refrigerant drawn off.

If drawn-off quantity does not correspond to specified fill quantity: supplement refrigerant and repeat test.

If capacity is correct, continue troubleshooting by pressure measurement.