Heating and Air Conditioning

Fault Code 0668

Vehicle voltage terminal 30

Diagnostic conditions
- Ignition on
- Battery voltage OK (11.4 to 14.5 V)
- Internal function test completed on air-conditioning system regulator control module
- Engine on
- Engine speed greater than 2,000 rpm

Possible causes of fault
- Vehicle voltage (battery voltage) exceeded
- Vehicle voltage (battery voltage) not reached
- Short circuit to ground
- Rear air-conditioning system regulator control module faulty

Affected pins
Air-conditioning system regulator control module, front: Plug E
- Pin 5 Term. 30 A (power supply)
- Pin 9 Term. 31 (ground supply line for ground pin 22)
- Pin 10 Term. 31 (ground supply line for ground pin 22)

Diagnosis/troubleshooting

Work Instruction 1:

Work Instruction 2 - 5:

Work Instruction 6 - 8:

Work Instruction 9 - 11: