2.2.207. SPN 4342, FMI 5, DEF backflow line heater control circuit open circuitΒΆ

Description

The EEM4 monitoring system has detected an open load on the DEF backflow line heater control circuit.

Possible causes are:

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