P008FEngine Coolant Temperature/Fuel Temperature Correlation
- Generic OBD-II code · Powertrain
- Turns on the check-engine light
- Matters for the ITP
- Needs a drive cycle to confirm a fix
- How the car detects it
- After the engine has been switched off long enough, coolant and fuel should have approached the same temperature. The engine control module compares the coolant temperature sensor with the fuel temperature sensor at the next cold start and sets P008F if they differ too much. From this alone it cannot tell which sensor is wrong, so both have to be checked. Regulations require such plausibility checks for input sensors; the exact conditions are manufacturer-specific.
- What you may notice
- Check engine light on
- Usually no drivability symptoms
- Cold-start behaviour may be affected
- Likely causes
- LikelyCoolant temperature sensor drifting
- LikelyFuel temperature sensor drifting
- PossibleContact resistance at a connector
- RareValues distorted, e.g. by an auxiliary heater
- Inspection (ITP)
- Matters for the ITP. While the check-engine light is on, the car fails the emissions check.
- Repair
- Easy · Often possible to do yourself.Typical cost: €40 – €200
- Related codes
Explanation from obdex (CC0), exactly as the app shows it. Guidance only; confirm with a workshop.