What it means
Voltage on the diesel fuel presence sensor signal line is below the expected window. Wire shorted to ground or sensor short.
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 low-circuit code sets when the signal falls below the expected range, commonly because the signal is shorted to ground, the sensor has failed, or its supply circuit is grounded.
Common causes
Most likely first.
- Signal wire shorted to ground
- Sensor fault
- Short to ground in the sensor supply circuit
Symptoms
- Check-engine light may be on
- Fuel contamination warning may appear
- Engine may run poorly or lose power
How to diagnose it
- Save freeze-frame data and check live sensor data and any fuel contamination warning to confirm that the fault is associated with a low or missing reading.
- Find the sensor using vehicle service information and inspect its connector and wiring for trapped, chafed, wet, or corroded areas that could short a circuit to ground.
- With the wiring diagram, check the signal wire for an unintended ground and inspect the sensor supply circuit for a ground short.
- Test the sensor ground, power, and signal connections for opens, shorts, or excessive resistance according to the manufacturer's specification.
- If the wiring and supply circuits pass, test the sensor and replace it if its output remains below the specified range.
Common fixes
- Repair a signal wire shorted to ground.
- Repair a short to ground or poor connection in the sensor supply wiring.
- Clean or replace a damaged or corroded sensor connector.
- Replace the diesel fuel presence sensor if it fails circuit testing.
Can I keep driving?
Limit driving and arrange diagnosis soon, especially if a fuel contamination warning appears or the engine runs poorly. Avoid heavy acceleration, and stop if power loss or rough running makes the vehicle difficult to control.
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.