2.2.191. SPN 4332, FMI 7, SCR system: DEF backflow line blocked or implausibleΒΆ

Description

The EEM monitoring system has detected an SCR system ERROR. The DEF supply module backflow line is defective.

Possible causes are:

  • The DEF backflow line is defective. (A possible blockage or a mechanical defect).
  • The DEF supply module backflow line connector 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 backflow line visually to detect any mechanical failures eg. the hose is flattened.
  • Examine the backflow connector visually to detect any mechanical failures.