Powertrain
generic / SAE
P012F
Engine Coolant Temperature / Engine Oil Temperature Correlation
Engine coolant and oil temperature readings disagree beyond plausible limits. The engine coolant temperature sensor feeds warm-up enrichment, fan control and closed-loop entry — a stuck-cold reading keeps the engine in open loop and rich forever.
SystemPowertrain
Typegeneric / SAE
GroupP0
Range / number1 / 2F
Possible causes
- One sensor drifted high
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
Inspection / repair
- Difficulty: easy
- DIY: possible
- Estimated cost: 40–350 €
- Estimated time: 0.3–2 h
- Component: ect sensor
- Component: oil temp sensor
- MIL / check engine light
- emissions-relevant
- drive cycle required
Sources
References
sae:J2012