P2066: Fuel Level Sensor B Circuit Range/Performance — what it means, the affected system and what to check before replacing parts.
Meaning, symptoms, causes and checks
Fuel-level sensor B: The monitored response fails its expected range or performance relationship, rather than specifying one failed component. B identifies the second named sensing channel, not a universal side of the tank. An electrical low/high result does not by itself prove the fuel level is physically low/high.
Affected system: Fuel-level measurement
Symptoms
- Fuel-level readings may fluctuate or disagree with the amount of fuel in the tank.
- Estimated driving range may be unreliable, and a warning indicator may appear.
Possible causes
- Fuel-level sender B may transmit an inaccurate signal.
- Corroded, damaged or loose wiring or connectors can interfere with the sender signal.
- A control-module issue is considered only after the sender and circuit have been checked.
What to check
- Confirm P2066 and related codes, then compare the gauge, live fuel-level reading and known tank contents.
- Inspect sender B wiring and connections near the tank for damage or corrosion.
- Check sender output or resistance against vehicle-specific service data before replacing parts.
Also written as: P2066-00, P206600 (some scan tools add the fault-type byte, e.g. -00).