Fuel Level Sensor 1 - Voltage Above Normal
The ECM is detecting a fuel level sensor voltage too high.
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What it means (plain English)
Inside the fuel tank, there's a float connected to a sensor. When the fuel level rises, the float moves up and changes the sensor's voltage. If the voltage goes above the normal range (usually above 4.5 volts), the system flags an error, thinking there's a problem with the sensor or wiring.
What the computer is actually seeing
The Engine Control Module (ECM) sees a fuel level input signal that's higher than the expected maximum voltage, typically over 4.5 volts, indicating a potential short or fault in the sensor.
What a healthy reading looks like
Normal fuel level sensor voltage should be between 0.5V (empty) and 4.5V (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. Inspect the wiring and connectors at the fuel level sensor for damage or corrosion. Did you find any issues?
- 2 - Yes: Repair the wiring or clean the connectors as necessary, then retest the system.
- 3 - No: Proceed to step 2.
- 42. Use a multimeter to measure the voltage at the fuel level sensor connector. Is the voltage over 4.5 volts?
- 5 - Yes: Replace the fuel level sensor and retest.
- 6 - No: Proceed to step 3.
- 73. Check the ECM for faults or errors. Are there any additional codes related to the fuel system?
- 8 - Yes: Diagnose those codes accordingly.
- 9 - No: The ECM may be faulty; consider replacement.
Common causes
- Shorted fuel level sensor wiring
- Faulty fuel level sensor
- Defective ECM
- Corrosion in connectors
Typical repair cost
$$$
Related codes
Frequently asked questions
Is it safe to drive with this code active?
It's best to fix this code soon as ignoring it could lead to incorrect fuel readings or running out of fuel unexpectedly.
Will this issue come back after repair?
If the wiring and sensor are properly replaced and moisture or damage are cleared, it shouldn't return.
Why do I see this code with low fuel readings?
A failing sensor may send incorrect signals, leading the ECM to interpret the fuel level inaccurately.
Working a real vehicle right now?
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