P0168: Fuel Temperature Too High

What P0168 means

P means powertrain (engine and transmission). The 0 marks a generic code defined by SAE, so the same number means the same thing across makes. The third character, 1, places it in the fuel and air metering subsystem; the last two digits identify the specific fault.

A fuel temperature sensor reports the temperature of fuel in the rail, pump or return line. Fuel density changes with temperature, so the engine computer uses it to correct injected quantity; on diesels and flex-fuel systems it is especially important.

What “Too High” means here

The fuel temperature sensor reported a value above what the module considers plausible or safe for the conditions. That can be real — the temperature or pressure really is too high — or a sensor reading wrongly, so confirm with an independent measurement before replacing parts.

What you may notice

Symptoms depend on the vehicle and on how the module responds to the fault. Any of these can accompany P0168:

• Often no noticeable symptom
• Hard hot starting on some engines
• Slight change in power or fuel use

Where to start diagnosing P0168

1. On a cold-soaked vehicle the fuel temperature should read close to ambient.
2. Inspect the connector and wiring; some sensors are combined with a fuel composition or pressure sensor.
3. Compare the reading with an independent temperature measurement where accessible.

Clear the code only after recording freeze frame data: it shows the engine speed, load and temperature at the moment the fault set, which is often the best clue to reproducing it.

Live data to watch

These standard OBD2 values relate to P0168. Support varies by vehicle; a value your car does not report will simply be missing.

Related codes

Codes from the same fuel temperature sensor family. If several are stored together, the shared part — wiring, a common reference voltage, or the component itself — is the place to start.

Further reading

• It cranks, but it will not fire

Frequently Asked Questions