3.2.425. SPN 522387, FMI 31, DEF dosing valve overheat protectionΒΆ

Description

The EEM4 monitoring system has detected a too high temperature in the SCR dosing valve, and the overheat protection is active. The DEF/AdBlue dosing is prevented, or the SCR tank is empty. A too high exhaust temperature without the DEF/AdBlue dosing will damage the SCR dosing valve.

Possible causes are:

  • The SCR tank is empty, and therefore the dosing valve is unable to dose.
  • The outlet exhaust gas temperature sensor is defective.
  • The outlet exhaust gas temperature is installed incorrectly.
  • Possible tampering.

Reaction in EEM

The FC is stored and the warning lamp is activated. The engine power will be reduced (Fuel limiting) above the warning limit to prevent overheating of the dosing valve. The CAN message indicates active fault.

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:

  • Refill the DEF tank with valid reducing agent (DEF/AdBlue).
  • Check the outlet exhaust gas temperature sensor assembly. Make sure the sensor is assembled according to the AGCO Power installation instructions.
  • Check the operation with another outlet exhaust gas temperature sensor to see if the sensor is defective.
  • A possible tuning chip may interfere with the exhaust gas temperature signal.

See Exhaust gas temperature sensor for reference.