What it means
The Fuel Level Sensor C reading is stuck and does not change as expected. The code does not by itself prove a mechanical float or resistor-wiper failure.
At a glance
- Usually lights the check-engine light
How it works
Fuel Level Sensor C reports fuel level through a signal that should change as fuel is used or added. P25DC sets when the reported value stays fixed when the control system expects it to move; that alone does not prove a jammed float or failed resistor wiper.
Common causes
Most likely first.
- Float arm jammed against tank wall, baffle or pump module
- Resistor wiper seized by varnish from old fuel
Symptoms
- Fuel gauge may remain fixed despite fuel use
- Fuel level warning may not reflect the actual fuel level
How to diagnose it
- Save freeze-frame data and check whether the Fuel Level Sensor C scan reading remains fixed despite a known change in fuel level.
- Compare the scan reading with the dashboard gauge and actual fuel level to establish whether the fault is limited to the sensor input.
- Inspect accessible wiring and the tank-module connector for damage, corrosion, or a loose connection that could freeze the signal.
- Following the manufacturer's procedure, check whether the sender float arm can move freely without catching on the tank wall, baffle, or pump module.
- If the float moves freely, test the sender output across its range for a stuck or irregular resistor-wiper reading.
Common fixes
- Repair a loose or damaged tank-module connector that interrupts the sensor signal.
- Free a float arm that is jammed against the tank wall, baffle, or pump module.
- Replace the sender if testing confirms a seized or defective resistor wiper.
- Repair damaged circuit wiring if continuity testing identifies an open or intermittent connection.
Can I keep driving?
The vehicle may drive normally, but the gauge can remain fixed and fail to warn before fuel runs out. Refuel early and track fuel use by mileage until the sensor reading changes reliably.
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.