P008F Engine Coolant Temperature/Fuel Temperature Correlation

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.

Likely causes

Symptoms

• Check engine light on
• Usually no drivability symptoms
• Cold-start behaviour may be affected

Repair estimate

Typical range across vehicles; the real cost depends on what the testing finds.

Parts involved

Related codes

References: law.cornell.edu, newtonnet.co.uk.