Test Point 27

TEST POINT 27
mC compressor control

DTC 170

1. Connect voltmeter to mC compressor relay terminal 86 and ground (activated via DmE relay)

Ignition "ON"

Display: 12 V

2. Connect voltmeter to relay terminal 30 and ground

Ignition "ON"

If voltage not present:
- Check heater relay No.18 (in the driver's footwell).
- Check wire from relay terminal 85 to DmE control module connector pin 62 for continuity.

3. Check A/C request

Connect voltmeter to control module connector pin 69 and ground

Ignition "ON"

Switch on A/C request

Display approx. 10 V