2.2.212. SPN 4344, FMI 4, DEF supply module heater: Control circuit short circuit to GROUND.ΒΆ

Description

The EEM4 monitoring system has detected a short circuit on the DEF supply module heater control circuit.

Possible causes are:

  • The DEF supply module heater wiring is defective. (Shorted to ground.)
  • The DEF heater relay is defective.
  • The DEF supply module heater is defective.

Reaction in EEM

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

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

Solution

First save the error log and then do the procedure that follows:

  • Examine the DEF supply module heater wiring, the connectors and the contact surfaces of the connector pins (possible oxidation). (see Supply module)
  • Examine the DEF heater relay wiring, the connectors and the contact surfaces of the connector pins (possible oxidation).
  • Try the operation with another DEF heater relay to see if the DEF heater relay is defective.