P008F
Engine Coolant Temperature/Fuel Temperature Correlation
Engine coolant temperature and fuel temperature readings are inconsistent — at long soak both should be near ambient and converge under load. One sensor has drifted.
- 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.
- One temperature sensor reading driftedCommon
Parts involved
- Coolant Temp Sensor
- Fuel Temp Sensor
P008F 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.