P0119
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.
- Check engine light: Yes
- Emissions related: Yes
- Repair difficulty: easy
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
Common causes
Ordered by how often each turns out to be the cause.
- ECT connector loose or corrodedCommon
- Sensor fails when warmPossible
- Wiring chafed near hot engine partsPossible
Parts involved
- ECT Sensor
- ECT Connector
- ECT Wiring
P0119 is a generic OBD-II code defined by SAE J2012. Exact wording and diagnostic procedure vary by manufacturer and model. Code definitions are drawn from the public-domain OBDex dataset; the workshop notes are our own.