Sensing Pressures

BOSCH speaks about diesel pressure sensors and pressure control valves.

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.


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. 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 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)


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.

Written by:

Published on: April 24, 2020

Filled Under: Sensors, Technical Articles

Web site:

Comments are closed.