Auxiliary Cabin Heater Control Module: Service and Repair

Replacing the control module.

Removing

Points to observe when replacing the control module




When changing an engine control module (ECM) from one car to another, remember to note any diagnostic trouble code (DTCs) before removing control module from the car.
Always check the control module connectors for bent or damaged terminals. This may have been the cause of the fault.
Location of components see Additional heater 912-D Locations.

Preparations

In the engine compartment:
Remove the battery holder.
Remove the heater connector at the bracket and disconnect the connector.
Remove the upper control module bracket retaining screw.
Remove the clamp around the ground lead and vacuum hose.

Raised car:
Remove the lower air baffle.
Remove the water pump mounting from the bracket and fold down the water pump.
Remove the lower control module bracket retaining screw.

Control module




Push the control module bracket upwards/inward to release the bracket brace from the side member.
Fold down the bracket with control module.
Position a screwdriver between the control module connector and its locking handle.
Twist the screwdriver to release the catch.
Continue to pull the locking handle outward until the connector comes away from the control module.
Remove control module from bracket.

Installing

Control module
Install a new control module on the bracket. Torque to 4.5 Nm .
Connect connector to the control module.
The connector will be pushed into place when the locking handle is pressed in completely.
Hook the bracket and control module into place on the side member.
Install both screws into the bracket. Tighten screws to 25 Nm .
Screw water pump into place on the bracket.

Finishing
Install the lower air baffle.
Lower the car.
Install a new clamp around the ground lead and vacuum hose.
Connect heater connector.
Install battery holder.
Check that the heater functions according to Test driving of Additional heater/Parking heater Initial Inspection and Diagnostic Overview.
Check that no diagnostic trouble codes (DTCs) have been stored while the repair was carried out.