What it means
The alternative fuel tank C level sensor reading is outside the expected range or does not behave as expected.
At a glance
- Usually lights the check-engine light
How it works
The tank C level sensor converts the alternative-fuel tank’s float position into a level reading for the control module. This range/performance code sets when that reading is implausible or fails to change as expected, even if the circuit is not simply open or shorted.
Common causes
Most likely first.
- Float stuck on guide rod
- Sensor characteristic drifted
- Sensor element aged beyond calibration window
Symptoms
- Check-engine or alternative-fuel system warning light
- Alternative-fuel tank level or remaining range may be inaccurate
- Fuel gauge reading may fluctuate
How to diagnose it
- Review freeze-frame data and live tank C level data, noting whether the reading is stuck, jumps, or disagrees with the gauge.
- Inspect the sensor connector and wiring for damage or poor contact that could distort the reading.
- Compare the tank C reading with the actual fuel level and observe whether it changes smoothly as the vehicle’s level changes.
- Check the float and guide rod for binding or sticking using the vehicle's specified access and safety procedure.
- Test the sensor response against the manufacturer's specification to identify drift or an aged sensor element.
Common fixes
- Free a sticking float or correct a binding guide rod if serviceable.
- Repair poor connector contact or damaged wiring affecting the sensor signal.
- Replace a sensor whose output has drifted or falls outside the manufacturer's specification.
Can I keep driving?
The tank C gauge and range estimate may be inaccurate or fluctuate, and alternative-fuel operation may be limited. Keep a conservative fuel reserve and avoid relying on the displayed range until the reading is verified.
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.