4.2.102. SPN 3031, FMI 4, DEF tank temp. sensor voltage below normalΒΆ

Description

The measured tank temp. sensor signal is below the normal operating range.

Possible causes are:

  • The DEF tank temp. sensor wiring is defective (shorted to ground)
  • The DEF tank temp. 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 DEF tank temp. sensor wiring, the connectors and the contact surfaces of the connector pins (possible oxidation).

NOTE: The DEF tank temp. and level sensors have a common reference GND

  • Check the operation with another tank temperature/level sensor to see if the tank temperature/level is defective.