4.2.330. SPN 94, FMI 18, Fuel main filter inlet pressure BELOW NORMALΒΆ

Description

The measured fuel pressure in the fuel filter falls below the normal range (<4bar). Possible causes for the low pressure indication are:

  • The fuel filters are full.
  • A leakage in the fuel system.
  • The fuel filter pressure sensor wiring is defective.
  • The fuel filter pressure sensor is defective.
  • A high pressure pump failure.

Reaction in EEM

The FC is stored and the warning lamp is activated. Engine power will be reduced (Degradation Level 1). The CAN message indicates active fault.

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:

  • The fuel filter service. The filters are full and need to be changed.
  • Check fuel system to detect any visible leakage.
  • Check the fuel filter pressure sensor wiring, the connectors and the contact surfaces of the connector pins (possible oxidation).
  • Check the operation with another fuel filter pressure sensor to see if the fuel filter pressure sensor is defective.
  • Check the high pressure pump operation and the fuel quality.

See Fuel pressure sensor sensor for reference.