4.2.51. SPN 1381, FMI 4, Fuel supply pump inlet pressure sensor voltage below normal.

Description

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

Possible causes are:

• The fuel supply pump pressure sensor wiring is defective
• The fuel supply pump pressure sensor power supply is not correct
• The fuel supply pump pressure sensor is defective

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. Engine functions that depend on the fuel supply pump 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 fuel supply pump pressure sensor wiring, the connectors and the contact surfaces of the connector pins (possible oxidation).(see Fuel supply pump inlet pressure sensor)
• Check the 5 V power supply to the sensor.(see Fuel supply pump inlet pressure sensor)
• Check the operation with another pressure sensor to see if the fuel filter pressure sensor is defective.(see Fuel supply pump inlet pressure sensor)