Fuel Level Sensor Circuit Low
The fuel level sensor is reading a low voltage signal.
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What it means (plain English)
The fuel level sensor in the tank is telling the computer that the fuel level is lower than it really is, often giving you a false empty reading.
What the computer is actually seeing
The Electronic Control Unit (ECU) expects a voltage signal from the fuel level sensor typically between 0.5V (empty) and 4.5V (full). A reading below 0.3V indicates a problem.
What a healthy reading looks like
Fuel level sensor voltage should be between 0.5V (empty) and 4.5V (full), ideally around 1V-3.5V when the tank is partially full.
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 fuel level at the tank. Is it low? If yes, refuel and see if the code clears. If no, continue.
- 22. Inspect the wiring and connectors at the fuel level sensor. Look for frays, corrosion, or loose connections. Repair as needed and retest.
- 33. Measure the voltage at the fuel level sensor connector with the key on (engine off). Are you getting 0.5V or higher? If not, check for an open circuit or grounding issues.
- 44. If the wiring is good and the sensor still reads low, replace the fuel level sensor and retest the system.
- 55. Clear the code and run the engine to see if the code returns. If so, consider inspecting the ECU for faults.
Common causes
- Defective fuel level sensor
- Wiring or connector issues
- Faulty ECU
- Grounding issues in the circuit
- Incorrect fuel calibration
Typical repair cost
$$
Related codes
Frequently asked questions
Is it safe to drive with this code?
It's moderate severity, so it’s best to fix it soon. You may run out of fuel unexpectedly.
Will this code come back?
If the underlying issue isn't fixed, yes, it will likely return.
Why does this code pair with SPN 135?
SPN 135 relates to fuel level, so issues with the sensor would cause both SPNs to trigger.
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