Coolant Heater A Over Temperature
Coolant heater A reports temperature above the protection threshold. Coolant flow blocked or thermistor failed.
Affected components
- Coolant heater a
- Coolant heater a control module
Common causes
- High likelihood: Coolant flow through heater blocked
- Medium likelihood: Thermistor failed
Diagnostic notes
- The malfunction indicator lamp may illuminate
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.