3.2.80. SPN 157, FMI 4, Rail 1 pressure sensor voltage below normalΒΆ

Description

The measured rail pressure signal is below the normal operating range (< 0,4 V).

Possible causes are:

  • The rail pressure sensor wiring is defective.
  • The rail pressure sensor power supply is not correct.
  • The rail pressure sensor is defective.

Reaction in EEM

The FC is stored and the warning lamp is activated. Engine power is heavily reduced (Degradation level 3). 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 rail pressure sensor is defective.

NOTE: The rail pressure sensor removal, inspection and replacement should be performed only by qualified injection system service personnel. Special instructions may apply.

See Rail pressure sensor for reference.