Fuel Temperature Sensor Circuit High
The fuel temperature sensor is reading a high voltage signal.
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What it means (plain English)
The fuel temperature sensor measures how hot the fuel is; a high signal usually means there's a wiring problem or the sensor is malfunctioning and sending too much voltage, typically over 5 volts.
What the computer is actually seeing
The ECM expects a voltage between 0.5 to 4.5 volts from the fuel temperature sensor. A reading above this range indicates a fault in the circuit, either due to high resistance, short-circuits, or sensor issues.
What a healthy reading looks like
Expected signal voltage from the fuel temperature sensor should range from 0.5V (cold fuel) to 4.5V (hot fuel).
Guided diagnostic — the DiagCoach way
Don't just throw parts at it. Walk through these in order — each step tells you whether to keep going or stop and fix what you found.
- 11. Visually inspect the wiring and connectors for the fuel temperature sensor. Look for damaged wires or loose connections.
- 22. Check the voltage at the fuel temperature sensor connector using a multimeter with the key on (engine off). Expected voltage should be between 0.5V and 4.5V.
- 3 - If voltage is above 4.5V, inspect for short circuits to power in the wiring.
- 4 - If voltage is within range, go to step 3.
- 53. Disconnect the fuel temperature sensor and measure the resistance across sensor terminals. Compare with manufacturer specifications.
- 6 - If resistance is out of spec, replace the fuel temperature sensor.
- 7 - If resistance is within spec, there may be an issue with the ECM.
Common causes
- Faulty fuel temperature sensor
- Damaged wiring or connectors in the sensor circuit
- ECM issues or faults
- Short circuit to power or ground in the fuel temperature sensor circuit
Typical repair cost
$$ - $$$
Related codes
Frequently asked questions
Is it safe to drive with this code?
It's best to address this code soon to avoid potential engine performance issues, but you may drive short distances.
Will this code come back after reset?
If the underlying issue isn't fixed, yes, the code will likely reappear.
Why does this code pair with others like SPN 1393?
These codes are often related as they indicate issues within the same sensor or system.
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