Operation CHARM: Car repair manuals for everyone.

Test Point 6



Test point 6
Supply voltage (5 volts)

Voltage too high
Voltage too low

Fault code 25

Diagnosis conditions
No control module fault stored.

Voltage too high
1. Unplug connector C from the heating/air-conditioning control.
2. Connect voltmeter to C 8 and ground. Switch on ignition.
Display: 0 volts

If the battery voltage is displayed, check the wiring harness for pinching and chafing damage.

3. Push on connector C.
4. Connect voltmeter to C 8 and ground. Switch on ignition.
Display: 5 ± 0.5 volts

If more than 5.5 volts are displayed, replace the heating/air-conditioning control.

Voltage too low
1. Unplug connector C from the heating/air-conditioning control.
2. Unplug all connectors from the valve drive motors.
3. Connect ohmmeter to connector C 8 and ground.
Display: Infinity Ohm

If 0 - 5 Ohms is displayed, check wiring harness for pinching and chafing damage.

4. Check potentiometer in the drive motors.

Temperature mixing valve:
Connect ohmmeter to pins 1 and 3.
Display: 4 - 5 kOhms at 23 °C

Footwell / defrost valve:
Connect ohmmeter to pins 1 and 3.
Display: 4 - 5 kOhms at 23 °C

Central valve:
Connect ohmmeter to pins 1 and 3.
Display: 4 - 5 kOhms at 23 °C

Outside air / recirculation valve:
Connect ohmmeter to pins 4 and 5.
Display: 4 - 5 kOhms at 23 °C