What it means
Fuel level sensor A (typically the float in the main fuel tank section) reports a value that does not change over a long driving distance — the float is mechanically stuck against the tank wall, baffle or pump module. Without level changes the EVAP monitor cannot run and remaining-range estimates are wrong.
At a glance
- Usually lights the check-engine light
- Affects emissions; the car can fail an emissions test
How it works
Fuel level sensor A reports the fuel level in the tank section it serves, usually through a float and variable electrical signal. P25B0 sets when the module sees that sensor A’s reported level stays fixed instead of changing over time, which can make the gauge and range estimate unreliable.
Common causes
Most likely first.
- Stuck float
- Bent float arm catching the tank wall
Symptoms
- Fuel gauge remains fixed or changes inaccurately
- Incorrect remaining-range estimate
- Check-engine light may come on
How to diagnose it
- Record freeze-frame data and compare fuel-level sensor A live data with the displayed gauge and the amount of fuel in the tank.
- Check whether the reading changes after a known refuel or during normal driving, allowing for the vehicle’s gauge filtering and update delay.
- Inspect sensor A’s accessible connector and wiring for damage, corrosion, or a loose connection.
- If access is required, inspect the sensor A float and arm for binding against the tank wall, baffle, or pump module.
- Test sensor A’s signal through its range using the manufacturer's procedure and compare it with the manufacturer's specification.
Common fixes
- Repair a damaged or loose sensor A connector or wiring.
- Free a float that is binding against the tank or an internal baffle.
- Correct a bent sensor A float arm that catches during movement.
- Replace sensor A if its float or resistive track does not move or report level properly.
Can I keep driving?
You can usually drive if the vehicle runs normally, but do not rely on the fuel gauge or remaining-range estimate; refuel early and track mileage. Running out of fuel can leave you stranded and may interrupt emissions monitoring.
A code shows where the control module detected a fault, not always which part failed. Check the causes in order and confirm with a test before replacing parts. Have several codes? Check them together
This is a generic code: it means the same on every make. The car’s maker may add more detail in its own service information.