Fault Code 1020

Fault code 1020

Activation of coolant pump

Diagnostic conditions
- Ignition on
- Battery voltage OK (11.4 to 14.5 V)
- Internal function test completed on air-conditioning system regulator control module

Possible causes of fault
- Short circuit to ground
- Open circuit/short circuit to B+

Affected pins
- 2-zone and 4-zone air conditioning systems

Air-conditioning system regulator control module, front: Plug C
- Pin 14 'Auxiliary heater (water pump activation)'
- Manual air conditioning

Air-conditioning system regulator control module, front: Plug A
- Pin 18 'Auxiliary heater water pump'

Diagnosis/troubleshooting
- 2-zone and 4-zone air conditioning systems






- Manual air conditioning