4.2.128. SPN 4332, FMI 11, SCR system ERROR: Pumped-Dosed quantities balance error

Description

The EEM4 monitoring system has detected an SCR system ERROR. Error is detected by correlating changes of urea dosing quantity to changes of DEF supply module duty cycle. DEF supply module duty cycle doesn’t correspond to actual dosing quantity.

Possible causes are:

  • The DEF pressure line is blocked
  • The DEF supply module main filter is defective
  • The DEF dosing valve is blocked
  • The used reducing agent (DEF/AdBlue) is contaminated
  • 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:

  • Commonly the pressure line is blocked. Remove the pressure line to detect the possible blockage.
  • Check for a possible blockage between the DEF supply module and the dosing module.
  • Remove the DEF dosing valve and check the nozzle of the dosing valve to see the possible blockage.
  • Change the DEF supply module main filter.
  • Check the used reducing agent for contamination and change it if necessary.
  • Check the operation with another DEF supply module to see if the supply module is defective.