What it means
Fuel-level sensor B reads above upper plausibility — open signal or short to B+. Wiring faults of this kind typically come from chafing, water ingress at connector seals, or pin push-back — a wiggle test on the harness while the code is active often confirms the location.
How it works
Fuel level sensor B is the secondary sender used on some vehicles to measure a saddle tank or auxiliary tank. The control module monitors its signal circuit. P2068 sets when the signal voltage is higher than expected, which can indicate an open signal wire or a short to battery voltage.
Common causes
Most likely first.
- Open signal line
- Connector pins corroded - high contact resistance
- Supply wire pinched against B+ source
Symptoms
- Check-engine light
- Fuel gauge may read inaccurately or erratically
- Low-fuel warning may not reflect the actual fuel level
How to diagnose it
- Record freeze-frame data and check for related fuel sender codes to see whether sensor B's high reading is constant or intermittent.
- Compare the gauge and sensor B scan-tool value with the actual fuel level, if available.
- Inspect sensor B's connector and harness for an open wire, a pushed-back pin, corrosion or wiring pinched against a battery-positive source.
- Use the manufacturer's wiring diagram to check signal-circuit continuity and test for a short to battery voltage.
- If the wiring passes, test fuel level sensor B itself using the manufacturer's procedure.
Common fixes
- Repair an open signal wire in the secondary sender circuit.
- Repair wiring shorted to a battery-positive source and secure the harness.
- Clean or replace a damaged sensor B connector and terminals.
- Replace fuel level sensor B if testing confirms it is producing an out-of-range signal.
Can I keep driving?
The vehicle is generally safe to drive, but sensor B may make the fuel gauge or low-fuel warning unreliable. Refuel early and track fuel use until the high signal fault is repaired.
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.