Fuel Temperature Sensor Voltage High
The fuel temperature sensor is reporting a voltage above its acceptable range.
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What it means (plain English)
The fuel temperature sensor measures how hot the fuel is. When it sends a voltage reading that’s higher than normal, it can indicate the fuel is much hotter than it should be, which can affect the engine's performance.
What the computer is actually seeing
The computer receives voltage from the fuel temperature sensor; typically 0.5V to 4.5V. A reading above 4.5V signals a problem.
What a healthy reading looks like
Fuel temperature sensor output should be between 0.5V to 4.5V; normal operating temperatures for diesel fuel are around 40°F to 140°F (4°C to 60°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. Inspect fuel temperature sensor wiring for damage or shorts. Is wiring intact?
- 22. Check the connector for corrosion or poor connection. Is the connector secure and clean?
- 33. Measure the voltage at the fuel temperature sensor connector. Is it above 4.5V?
- 44. If voltage is high, replace the fuel temperature sensor and retest. If voltage is normal, check the ECM for faults.
Common causes
- Faulty fuel temperature sensor
- Wiring issues (short to power)
- Connector corrosion or damage
- ECM problems
Typical repair cost
$$
Related codes
Frequently asked questions
Is it safe to drive my vehicle with this code?
It is not recommended to drive as excessive fuel temperatures can lead to engine damage.
Will this code come back after clearing it?
If the underlying issue is not resolved, the code will likely return.
Why does this code sometimes pair with SPN 1145?
SPN 1145 indicates fuel temperature sensor voltage low, showing that both high and low voltage issues can be related to sensor or wiring problems.
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