Engine Coolant Temperature Sensor Circuit Malfunction
A general fault has been detected in the engine coolant temperature (ECT) sensor circuit. The ECU uses ECT for fuel enrichment during cold start, fan control, and closed-loop entry timing.
Affected components
- Coolant temperature sensor
- Coolant temperature sensor wiring
Common causes
- High likelihood: Coolant temperature sensor failed
- Medium likelihood: Wiring or connector fault
Possible symptoms
- Check engine light on
- Cooling fan runs constantly or not at all
- Cabin heater weak or excessively hot
- Possible long warm-up time or hard cold start
Diagnostic notes
- The malfunction indicator lamp may illuminate
- This code can affect emissions
- A drive cycle may be required after repair
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.