Fault Code 31

Fault Code 31

Fresh-Air Blower Motor - Voltage Deviation Too Small/Too Great

Diagnostic conditions
- Ignition on
- Blower switched on
- No control unit fault stored
- No sensor supply voltage fault stored (5 V)

Possible cause of fault
- Fuse C7 faulty
- Fuse D6 faulty
- Fault in lines between fresh-air blower relay or blower regulator (driver) and fresh-air blower.
- Fresh-air blower relay faulty
- Blower regulator (driver) faulty
- Air-conditioning system regulator faulty

Affected pins
Plug B, pins 10, 11 and 12

Diagnosis/troubleshooting

Work Instruction 1 - 2:

Work Instruction 3 - 6:

Work Instruction 7 - 10:

Work Instruction 11 - 19: