Engine Coolant Heater A Control Circuit/Open
Engine Coolant Heater A Control Circuit/Open: the control circuit is open. Likely a broken wire, disconnected connector, or failed actuator.
Affected components
- Coolant heater a
- Heater wiring
Common causes
- High likelihood: Wiring break
- Low likelihood: Pin pushed back out of connector body
- Low likelihood: Cracked solder joint inside the module or sensor
Diagnostic notes
- The malfunction indicator lamp may illuminate
- This code can affect emissions
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.