Diesel Particulate Filter Differential Pressure Sensor A Circuit Range/Performance
A sensor measures the pressure difference before and after the particulate filter (DPF) through two pipes. From it the ECU works out how much soot there is.
What the car has detected
The pressure the sensor gives is not consistent: for example it does not read nearly zero with the engine off or does not rise when accelerating.
With a false reading regenerations may fail or run too often, and the filter may fill up. Have it checked soon.
Symptoms
- Engine or DPF warning light on
- More frequent or unfinished regenerations
- Loss of power or limp mode
Possible causes
- Sensor pipes cracked, loose, swapped or blocked
- Faulty differential pressure sensor
- Particulate filter full of ash
Checks for the garage
- Check the sensor’s two pipes and their order
- Check the live pressure with the engine off and when revving
- Check the filter’s soot and ash load with the diagnostic tool
Next step
Ask for the sensor’s two pipes to be checked first, as they often crack or block, and then the sensor.
Go to a garage in the next few days and avoid lots of short trips meanwhile.