What does it mean?
P1457 is a Powertrain (engine, transmission, fuel system) fault code. It indicates: Fuel Tank Level Sensor Circuit Malfunction .
Symptoms
- MIL on with an inaccurate, stuck or jumping fuel gauge
- Low fuel warning lamp on with a full tank, or never coming on at all
- Range to empty calculation unavailable or clearly wrong
- EVAP leak monitors do not run because the level condition is never satisfied
- Engine performance unaffected, so the fault is mainly an information problem until fuel actually runs low
Likely causes
- Worn or burnt resistive track on the sender card
- Float arm sticking, bent or detached from the sender
- Open or shorted wire between the sender and the module
- Corroded or water damaged connector at the tank flange
- Poor ground connection for the sender assembly
- Contaminated fuel leaving deposits on the sender contacts
- Damaged harness under the rear seat or along the underbody
How to fix it
- Compare the fuel level value in live data with the real tank content right after refuelling
- Disconnect the sender connector and observe whether the reported value moves to the opposite extreme, which points at the sender
- Inspect the tank flange connector for corrosion, moisture and loose terminals
- Measure sender resistance across its full float travel when the unit is accessible, watching for dead spots
- Test the signal wire for continuity and for shorts to ground and to power
- Perform a voltage drop test on the sender ground
- Replace the sender unit if its track is worn, or repair the wiring fault, then verify the gauge tracks correctly through a full tank