Air Conditioner Test (R 134a)

64 50 ... - Air conditioner test (R 134a)

Before A/C efficiency test, satisfy following conditions:
1. - Provide a MoDiC or DIS. 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 work bay with an ambient temperature between 20° C and 30° C.

Re 1:
Connect MoDiC or DIS to car 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 vehicle interior:
- A/C button is not activated during heating up.

- Close all windows and doors.

- Set recirculated air mode.

- Select air distribution mode for footwell and defrosting.

- Maximum temperature setting.

- Maximum fan stage.

- Run engine at approx. 2000 rpm until operating temperature is reached, then idle speed.

A/C efficiency test:
Turn on A/C compressor at a vehicle interior temperature of 50° C.
After 3 - 4 minutes, the evaporator sensor temperature must be ≤ 15° C.
Draw off A/C system Drawing off, Evacuating and Filling A/C System (R 134a) 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:
A/C systems with uncontrolled compressors only:
If necessary, then continue troubleshooting by pressure measurement.