What it means
Voltage on the diesel fuel presence sensor signal line is above the expected window. Wire shorted to B+ or sensor open.
At a glance
- Usually lights the check-engine light
- Affects emissions; the car can fail an emissions test
How it works
The diesel fuel presence sensor sends a signal to the engine control module for fuel-system monitoring. This high-circuit code sets when the signal rises above the expected range, often because the signal is shorted to power, the circuit is open or resistive, or the sensor has failed.
Common causes
Most likely first.
- Signal wire shorted to B+
- Open or high-resistance signal/ground circuit
- Sensor fault
Symptoms
- Check-engine light may be on
- Fuel contamination warning may appear
- Engine may run poorly or lose power
How to diagnose it
- Record freeze-frame data and check live sensor data and any fuel contamination warning to confirm whether the signal is high or fixed.
- Locate the sensor using vehicle service information and inspect its connector and harness for loose terminals, corrosion, damage, or contact with a power feed.
- Use the wiring diagram to check the signal wire for a short to power and inspect the signal and ground paths for opens or excessive resistance.
- Check sensor power, ground, and signal connections against the manufacturer's specification to distinguish a circuit fault from a failed sensor.
- If the circuits test correctly, test the diesel fuel presence sensor and replace it if its output remains above the specified range.
Common fixes
- Repair a signal wire shorted to a power feed.
- Restore an open or high-resistance signal or ground connection.
- Clean or repair loose or corroded sensor connector terminals.
- Replace the diesel fuel presence sensor if it fails testing.
Can I keep driving?
Limit driving and arrange diagnosis soon, particularly if the fuel contamination warning is on or the engine has lost power. Avoid heavy loads and stop if rough running or power loss worsens.
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.