A/C Efficiency Check

Air-Conditioning Efficiency Measurement

Air-conditioning efficiency measurement (R134a)

64 50...

Before the air-conditioning efficiency measurement, a number of conditions must be met:
1. Ensure the electrical system integrity by checking the fault memory (no faults in the fault memory).
2. Provide a thermometer with a separate display element.

Position a thermometer with a separate display element approx. 5 cm under the headlining at the height of the B-pillar. Route the display element from the vehicle interior outwards.

3. Perform the check in a suitable work bay with an ambient temperature between 20 °C (68 °F) and 30 °C (86 °F).

Heat up the vehicle interior:
- The A/C button is not activated on heating up
- Close all windows and doors
- Set the recirculated-air mode
- Select air distribution footwell and defrosting
- Maximum temperature setting
- Maximum blower speed
- Run the engine at approx. 2000 rpm until operating temperature is reached, then idle speed

Air-conditioning efficiency measurement:
Once the vehicle interior has reached a temperature of 50 °C (122 °F), switch on the air-conditioning compressor. After 3 - 4 minutes, the temperature at the evaporator temperature sensor must be d 15 °C (59 °F).