4.2.101. SPN 3031, FMI 31, DEF tank temperature value abnormal rate of changeΒΆ

Description

The EEM monitoring system has detected that DEF tank temperature sensor value is implausible.

Possible causes are:

  • The sensor wiring contact is loose
  • The sensor wiring is defective.
  • The sensor 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:

  • Check the temperature sensor wiring, the connectors and the contact surfaces of the connector pins (possible oxidation).
  • Check the operation with another temperature sensor to see if the sensor is defective.