4.2.62. SPN 157, FMI 21, Rail Pressure control: Pressure raw value is below minimum offsetΒΆ

Description

The EEM4 monitoring system has detected a rail pressure sensor error. Rail pressure is below offset during startup or afterrun. Possible causes are:

  • The rail pressure sensor is defective.
  • The rail pressure sensor wiring is defective.

Reaction in EEM

The FC is stored and the warning lamp is activated. The CAN message indicates active fault. The engine functions dependent on the rail pressure are not active.

Solution

First save the error log and then erase it. Restart the ECU after erasing the error log. If the fault occurs again during the next driving cycle, check the following paths:

  • Check the rail pressure sensor wiring, the connectors and the contact surfaces of the connector pins (possible oxidation).
  • Check the 5 V power supply to the sensor.
  • Check the operation with another rail pressure sensor to see if the sensor is defective.

See Rail pressure sensor sensor for reference.