3.2.246. SPN 4376, FMI 3, DEF pump direction valve low side short circuit to high SOURCEΒΆ

Description

The EEM4 monitoring system has detected a short circuit to high source on the DEF pump direction valve low side.

Possible causes are:

  • The DEF supply module wiring is defective. (Shorted to high source.)
  • The DEF supply module is defective.

Reaction in EEM

The FC is stored and the warning lamp is activated. The CAN message indicates active fault.

NOTE: The present fault is classified as an emission related fault. Engine power will be reduced after a certain time defined by an authority.

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 DEF supply module wiring, the connectors and the contact surfaces of the connector pins (possible oxidation). Measure the DEF pump direction valve low side to the engine ground to detect the short circuit.
  • Check the operation with another DEF supply module to see if the supply module is defective.