Fuel Level Sensor Circuit Malfunction
What does B1412 mean?
The B1412 code means the vehicle's onboard diagnostic system has detected: Fuel Level Sensor Circuit Malfunction. This is a moderate severity code.
Common Symptoms
- Fuel gauge reads empty when tank is full
- Fuel gauge stuck at one position
- Low fuel warning light always on or never on
- Fuel gauge fluctuates erratically
- Range estimate wildly inaccurate
Probable Causes (Ranked by Likelihood)
- Failed fuel level sending unit in tank Very High
- Corroded fuel level sensor connector High
- Wiring fault between fuel tank and instrument cluster Moderate
- Instrument cluster fuel gauge circuit failure Low
Step-by-Step Diagnostic Procedure
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Read fuel level sensor PID with scan tool
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Check fuel level sensor resistance at tank connector
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Inspect wiring from fuel tank to body harness
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Test fuel gauge by applying known resistance to circuit
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Check for fuel tank ground corrosion
Frequently Asked Questions
Can I run out of gas if the fuel gauge is wrong?
Yes. If the gauge reads higher than actual fuel level, you could unexpectedly run out of fuel. Track your mileage and fill up based on miles driven until the gauge is repaired.
Where is the fuel level sending unit?
It is located inside the fuel tank, attached to the fuel pump assembly. Replacing it usually requires dropping the fuel tank or accessing it through a tank access panel if the vehicle has one.
Why does my fuel gauge bounce around?
An erratic gauge usually indicates a worn contact on the fuel level sending unit variable resistor. As the float moves, it hits worn spots on the resistor causing the reading to jump.