Lost Communication with Auxiliary Heater Control Module
The Auxiliary Heater Control Module has stopped transmitting on the vehicle data bus, so other control units no longer receive its messages. The auxiliary or parking-heater control is lost. Typical causes are loss of power or ground at the module, an open or shorted CAN/LIN bus wire, a connector fault, or an internal module failure.
Affected components
- Auxiliary heater module
- Can bus wiring
Common causes
- High likelihood: Auxiliary heater unpowered
- Medium likelihood: CAN wiring to auxiliary heater broken
- Low likelihood: Gateway module routing CAN messages incorrectly
Possible symptoms
- Multiple warning lights may illuminate
- Affected modules may go into limp mode or shut down
- Specific functions inoperative depending on module
- Diagnostic tools may show communication faults
Related codes
Sources
Diagnostic information is provided for reference only. Confirm the code with a compatible scan tool and follow the vehicle manufacturer's service procedures before replacing components.