4.2.181. SPN 4792, FMI 14, SCR catalyst overtemperatureΒΆ

Description

The EEM4 monitoring system has detected abnormally high SCR catalyst temperature. Temperature is measured with two exhaust temperature sensors: the first sensor is before and the second is after the catalyst.

Reaction in EEM

The FC is stored and the warning lamp is activated. The CAN message indicates active fault. Engine power will be derated due the catalyst temperature.

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:

  • Check engine The air filter condition for possible impurities, dust in filter
  • Check the boost pressure level and the possible leaks in the pressure pipes.
  • Check the exhaust temperature sensor wiring, the connectors and the contact surfaces of the connector pins (for possible oxidation).(see Exhaust gas temperature sensor)