Engine Fuel Temperature Sensor Low or High
The fuel temperature sensor is reporting an out-of-range temperature.
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What it means (plain English)
The engine's fuel temperature sensor is telling the computer that the fuel is either too hot or too cold, which can affect performance and fuel efficiency.
What the computer is actually seeing
The Engine Control Module (ECM) expects a fuel temperature reading between 0-90°C (32-194°F). If it sees a value below -20°C (-4°F) or above 120°C (248°F), it will throw a code.
What a healthy reading looks like
Fuel temperature should be between 0°C to 90°C (32°F to 194°F) under normal operating conditions.
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.
- 1Check the fuel temperature sensor connector for corrosion or loose wires.
- 2Measure the resistance of the fuel temperature sensor with a multimeter; compare the readings to specifications of 10-1600 ohms at temperatures of -20°C to 120°C.
- 3Inspect wiring for damage or shorts, especially near heat sources or moving components.
- 4If sensor and wiring check out, check for signs of fuel contamination or environmental factors affecting the fuel temperature.
- 5If all else fails, consider ECM replacement after verifying all external factors are within spec.
Common causes
- Faulty fuel temperature sensor
- Wiring issue or connector problem
- Faulty ECM
- Fuel near freezing or boiling point due to environmental conditions
- Contaminated fuel causing erratic readings
Typical repair cost
$$$
Related codes
Frequently asked questions
Can I still drive the vehicle with this code?
Yes, but you may experience reduced performance and fuel efficiency until it's fixed.
Will this code return after repair?
If the repair is done correctly and all connections are solid, it should not return.
Why does this code appear with SPN 1209?
SPN 1209 (Fuel Temperature Sensor Alternative) often accompanies faults in the same sensor circuit, indicating possible issues with the same system.
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