What does it mean?
This is a plausibility fault on the tank A level sender for the gaseous fuel system, not a wiring failure. The reported level stays within its electrical limits, but it does not behave the way a real tank would: it may never change during a long drive, it may fail to rise after a documented refuelling event, or it may move in a direction that consumption cannot explain. The module cross-checks the level signal against fuel consumed, tank pressure and temperature, and against the refill detection, so a sender that sticks or drifts is caught even though no circuit code is present. The consequence is a misleading gas gauge and an unreliable low fuel warning, which can leave the driver stranded on gas without notice. Mechanical problems inside the sender dominate this failure mode.
Symptoms
- Gas gauge that stays at one reading for a long time and then drops suddenly
- Gauge that does not rise properly after filling the tank
- Low fuel warning that comes on far too early or far too late
- Running out of gas with fuel apparently still showing on the gauge
- MIL (check engine lamp) on with a gaseous fuel rationality fault stored
- Range estimate that disagrees with actual consumption
Likely causes
- Float arm sticking, bent or fouling the inside of the tank, so the level freezes at one point
- Worn or dirty resistive track giving a dead spot over part of the travel
- Magnetic coupling on an LPG multivalve slipping or the external sender being knocked out of alignment
- High resistance in the signal or ground circuit shifting the reported level without leaving the valid range
- Incorrect sender fitted after a tank or multivalve replacement, with a different resistance range
- Sender not calibrated to the module after a repair or a gas system installation
- Level information being cross-checked against a faulty pressure or temperature sensor
How to fix it
- Note the indicated level, then add a measured quantity of gas and confirm the value rises proportionally
- Read the raw sender voltage or resistance in live data through a full tank cycle and look for a section where the value stops changing
- Measure sender resistance at the connector across the float travel where the design allows access, checking for dead spots
- On LPG multivalve systems, verify the external sender is correctly seated and aligned with the internal magnet
- Perform voltage drop tests on the signal and ground circuits; added resistance shifts the level without setting a circuit code
- Confirm the correct sender part is fitted and that any required level calibration procedure has been carried out
- Replace the level sender or multivalve assembly when a dead spot or sticking float is confirmed and the wiring is good