Engine Fuel Temperature Sensor Voltage Too High
Indicates the fuel temperature sensor signal is above normal range.
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What it means (plain English)
The engine control module is reading a fuel temperature signal that’s higher than it should be, which can affect performance if the fuel overheats.
What the computer is actually seeing
The ECM expects the fuel temperature sensor to send a voltage between 0.5V to 4.5V. If the voltage exceeds 4.5V, this code is triggered.
What a healthy reading looks like
Normal fuel temperature sensor voltage should range from 0.5V at -40°C to 4.5V at 150°C.
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 fuel temperature sensor and wiring for damage or disconnection. Decision: If damaged, repair/replace. If not, proceed.
- 22. Check the fuel temperature sensor voltage using a multimeter. Connect to the sensor signal wire with the ignition on (engine off). Decision: If voltage is over 4.5V, sensor is likely faulty. If normal, proceed.
- 33. Verify connector integrity at the sensor and ECM. Look for corrosion or loose connections. Decision: Repair connectors if damaged; otherwise, continue to check ECM.
- 44. If voltage is HIGH at the sensor but normal after the connector, suspect a fault in the ECM or its programming. Consider reprogramming or replacement.
Common causes
- Damaged fuel temperature sensor
- Short circuit in wiring
- Faulty engine control module (ECM)
- High fuel temperatures due to engine problems
Typical repair cost
$$$ - $$$$ (parts + labor)
Related codes
Frequently asked questions
Is it safe to drive with this code?
It's best not to drive until the issue is resolved; high fuel temperatures can cause engine performance issues.
Will this code come back after clearing?
If the underlying issue isn’t fixed, yes, the code will likely return.
Why does this code sometimes appear with SPN 5248?
SPN 5249 and SPN 5248 are related as they both deal with fuel temperature but can indicate different severity levels or sensor failures.
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