Engine Fuel Temperature Sensor 1
Fuel temperature is out of range for engine operation.
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What it means (plain English)
The temperature sensor for the engine's fuel is reading too high or too low, which can affect how the engine runs.
What the computer is actually seeing
The ECM (Engine Control Module) expects the fuel temperature to be within a certain range and alerts when it deviates—generally below -40°C (-40°F) or above 100°C (212°F).
What a healthy reading looks like
Normal fuel temperature should be between 10°C and 85°C (50°F to 185°F).
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. Check the wiring and connectors from the fuel temperature sensor for damage or corrosion. Repair or replace as necessary. Decision: Is wiring/connector okay? (Yes/No)
- 22. Using a multimeter, test the fuel temperature sensor signal output. Expected voltage: 0.5V at -40°C and 4.5V at 100°C (use a reference chart). Decision: Is voltage output within spec? (Yes/No)
- 33. Inspect the fuel system for blockages or restrictions that could affect temperature readings (like a clogged filter). Decision: Any blockages found? (Yes/No)
- 44. If all previous steps are okay, consider reprogramming or updating the ECM to ensure it’s reading correctly.
Common causes
- Faulty fuel temperature sensor
- Wiring issues or connector corrosion
- Fuel line blockage or failure
- ECM software issue
Typical repair cost
$$
Related codes
Frequently asked questions
Is it safe to drive with this fault code present?
It’s generally safe for short distances but can lead to performance issues—address it soon.
Will this code come back after clearing?
If the underlying issue isn't resolved, yes, it will return.
Why do I see this code with others like SPN 681?
They can indicate related fueling or temperature sensor issues.
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