Fitted into a diesel engine, a diesel pressure sensor functions to relay a pressure drop in the common rail system to the ECU. The ECU uses this information to restore the pressure via a high-pressure pump.
When modern vehicles experience common rail system problems, faulty injectors or pumps are key suspects as causes for failure. However, a faulty fuel pressure sensor or metering control valve can cause similar symptoms to emerge.
Common Diesel Pressure Sensor Fault Codes
The diesel pressure sensor is the weak point in the loop system as it is very prone to failure. Thus, when a common rail system fails, it is imperative to conduct a full diagnostic check on the vehicle.
Two common error codes that commonly occur when there is a problem with the diesel pressure sensor are:
P0193 – Fuel rail sensor circuit high input
The power control module (PCM) has detected that the fuel pressure is not within the range that has been predetermined by the vehicle manufacturer.
P0087 – Fuel rail pressure too low
Typically, when there is a problem within the fuel delivery system that causes the fuel pressure to be too low.
Symptoms of a Faulty Diesel Sensor
A faulty diesel sensor can also cause the following symptoms to arise:
- Slower crank time
- Loss of power on power stroke
- Difficulty in starting engine
- Cutting out of power
- Rough, erratic running
Replacing a Faulty Diesel Sensor
Replacing a faulty diesel pressure sensor is comparatively easy within the common rail system. Whilst the ECU memory needs to be cleared of all existing fault codes, the engine does not require recoding when replacing a faulty diesel pressure sensor.
Bosch diesel pressure sensors provide very reliable and accurate measurements at extremely fast response times to ensure that the vehicle continues to run as intended. With built-in circuit protection, it ensures that corresponding electronics and computer systems stay unharmed to provide high reliability in pressure sensing, despite the harsh environment it operates within. The sturdy design of Bosch diesel pressure sensors integrates thermal stability and vibration resistance.
The extensive range of diesel pressure sensors from Bosch covers all vehicle manufacturers including BMW, Peugeot, Mercedes-Benz, Citroën, Ford, Vauxhall and VAG.
Application highlights include:
- 0281006158 for Vauxhall Combo 1.6 CDTi (2011>)
- 0281002842 for Mercedes-Benz Sprinter 3.0 CDi (2009-2014)
Pressure Control Valves from Bosch
Bosch’s diesel accessories also extend to diesel pressure control valves that are also known as metering units. The diesel pressure control valve is located by the high-pressure pump as it controls the precise amount of fuel required by the injectors to the common rail.
With more than 20 parts available currently in range, highlights include:
- 0928400680 for Alfa Romeo Mito 1.6 JTDM (2008>)
- 0928400498 for BMW 3 Series D (2006-2013)
- 0928400681 for Ford Focus 1.6 TDCi (2005-2012)
NOTE: Bosch pressure control valves are not currently catalogued on MAM Autocat but are available via the F:Drive.
Bosch diesel pressure sensors and pressure control valves are available from FPS via the F:Drive. For more information, please speak to your local FPS representative.