Fuel Temperature Sensor Circuit Low
Indicates a low voltage reading from the fuel temperature sensor.
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What it means (plain English)
The fuel temperature sensor is responsible for measuring the temperature of the diesel fuel in the tank or fuel line. If it reads a voltage lower than expected, the computer thinks something might be wrong.
What the computer is actually seeing
The Engine Control Module (ECM) looks for a voltage signal around 0.5V to 4.5V from the sensor based on the fuel temperature. A reading below 0.5V indicates a fault.
What a healthy reading looks like
Normal operation shows fuel temperatures between 10°C to 60°C (50°F to 140°F), with corresponding sensor voltage typically between 0.5V to 4.5V.
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. Inspect wiring and connectors to the fuel temperature sensor for damage or corrosion. Repair or replace as necessary. Decision point: If damaged, repair and retest. If not, proceed.
- 22. Measure the voltage at the fuel temperature sensor connector with the engine running. Expected voltage is between 0.5V and 4.5V. Decision point: If voltage is out of range, proceed to step 3. If voltage is within range, consider replacing the ECM.
- 33. Disconnect the fuel temperature sensor and measure its resistance. It should show a specific resistance based on the temperature. Decision point: If resistance is not within expected range, replace the sensor. If OK, further investigate ECM issues.
Common causes
- Wiring issues (shorts, opens, or corrosion)
- Faulty fuel temperature sensor
- Poor connection at the sensor or ECM
- ECM calibration error
Typical repair cost
$$
Related codes
Frequently asked questions
Can I still drive the vehicle with this code?
It's drivable but may cause poor fuel management and potential starting issues in cold conditions.
Will this code come back after a reset?
If the issue isn't fixed, yes, it will reappear.
Why does this code pair with other codes?
Related codes often point to issues in the same sensor circuit or system.
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