P0168Fuel Temperature Too High
- Generic OBD-II code · Powertrain
- Turns on the check-engine light
- Can trigger limp mode
- How the car detects it
- P0168 is not a sensor fault but an operating condition, almost only on diesels: the fuel temperature sensor reports fuel hotter than a protective limit. The fuel heats up through the return flow from the high-pressure pump and injectors, especially with little fuel in the tank, at idle after full load, in hot weather or with a failed fuel cooler; one manufacturer patent names about 80 °C as the upper limit to protect seals, against a normal range of roughly 5–60 °C. On Saab's Bosch EDC16 diesels the code means an engine protection function is active and injection quantity is reduced. No manufacturer threshold was found, and GM's and Ford's diesel summaries do not use P0168. Whether the warning light comes on depends on the manufacturer.
- What you may notice
- Loss of power, limp mode (reduced injection quantity)
- Warning light depending on manufacturer
- Occurs in heat, at full load, with little fuel in the tank
- Likely causes
- LikelyFuel cooler (air or water cooler in the return) dirty or faulty, coolant circuit disturbed
- PossibleVery little fuel in the tank at high load or heat
- PossibleExcessive return flow from worn high-pressure pump or injectors, or faulty overflow valve
- PossibleFuel temperature sensor drifting and reading too high
- RareEngine overheating or overload (trailer, gradient)
- Repair
- Medium · Usually a job for a workshop.Typical cost: €80 – €600
- Related codes
Explanation from obdex (CC0), exactly as the app shows it. Guidance only; confirm with a workshop.