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

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

Observe the following conditions prior to the A/C performance test:
1. Provision of a diagnosis 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 diagnosis 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 passenger compartment.

Re 3:
Heat passenger compartment:
- "A/C button" is not activated during the heating process
- Close all windows and doors.
- Set air recirculation function.
- 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 (28 °C)
- Maximum blower speed (adjust 9 pixels from 9 possible on front A/C control panel)
- Run engine at approx. 2000 rpm until operating temperature is reached, then idle speed.

Air-conditioning performance test:
Turn on A/C compressor via "A/C button" at a vehicle interior temperature of 50 °C.

Vehicles with MAX AC button ("MAX"):
- Activation of MAX AC (= maximum cooling power)

Vehicles without MAX AC button ("MAX"):
- Set maximum cooling power by means of following steps:
- Temperature setting = 16 °C
- Blower setting 9 pixels of 9 possible
- Stratification maximum cold (4 blue bars)

Evaporator sensor temperature must be d 15 °C after 3--4 minutes at approx. 2000 rpm.

Draw off A/C system 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 capacity is correct, continue troubleshooting by pressure measurement.