Fuel Temperature Sensor 1 - Voltage Above Normal Operating Range

The fuel temperature sensor measures how hot the fuel is. If it's sending too high a voltage signal (over 4.5 volts), the computer thinks there's a problem and sets this code.

The engine control module (ECM) sees a fuel temperature sensor signal voltage greater than 4.5 volts, which is outside the normal operating range of 0.5 to 4.5 volts for most systems.

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.

1. 11. Check the vehicle's fuel levels and ensure adequate fuel supply; low fuel can affect sensor readings. Decision: If fuel is low, fill and retest; if ok, proceed.
2. 22. Inspect wiring and connectors to the fuel temperature sensor for damage or corrosion; look for 5-volt reference signal and ground. Decision: Repair any issues found or proceed with testing the sensor.
3. 33. Use a multimeter to measure the voltage output of the fuel temperature sensor while the engine runs. Expected reading: Between 0.5 and 4.5 volts. Decision: If it’s out of range, replace the sensor; if in range, suspect ECM issues.
4. 44. Take a look at the fuel temperature sensor data using a scan tool to verify accuracy under different operating conditions. Decision: If data is erratic, replace the sensor or test the ECM.

• Faulty fuel temperature sensor
• Wiring short to power
• Poor ground connection
• Connector corrosion or damage
• ECM malfunction

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