U0166
Lost Communication With Auxiliary Heater Control Module
Severity: MEDIUM
Symptoms
- Auxiliary heater does not work
- Error indication on the instrument panel
- Reduced comfort in the cabin in winter
- Other CAN bus errors are possible
Causes
- Broken or damaged CAN bus wires
- Heater module power supply problems
- Heater control module malfunction
- Corrosion of contacts or connectors
- Problems with the main ECU
How to Fix
- Check the integrity of the wiring harness to the heater module
- Check the power supply and ground of the module
- Inspect connectors for corrosion
- Scan the CAN bus for other errors
- If necessary, replace the heater control module