Engine Coolant Temperature Sensor Circuit Intermittent
The ECU detects intermittent signal dropouts on the engine coolant temperature (ECT) sensor circuit. Fault not constantly present, typically due to loose connector, chafed wiring or a sensor failing thermally.
Affected components
- Ect sensor
- Ect connector
- Ect wiring
Common causes
- High likelihood: ECT connector loose or corroded
- Medium likelihood: Sensor fails when warm
- Medium likelihood: Wiring chafed near hot engine parts
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.