P0087 - Fuel Rail/System Pressure – Too Low
The ECM will control fuel pressure using some form of regulator and monitor Fuel Rail pressure to ensure that there is a stable fuel supply to allow accurate injection quantity.
Fault Code Explained
The ECM is receiving a signal from the fuel pressure sensor that indicates the pressure is below what is expected / required, this could be due to an actual fuel pressure that is low or due to an incorrect signal from the fuel pressure sensor
Testing of the actual fuel pressure using a pressure gauge is required to establish if the sensor is providing an accurate reading of the actual fuel pressure
If the actual fuel pressure matches the fuel pressure sensor output further testing of the fuel system is required to trace the cause of the low fuel pressure. Due to the variety of systems and control methods it is recommended to follow the manufacturers test plan
If the actual fuel pressure is different from the sensor output, test the sensor wiring and sensor.