4.2.81. SPN 1761, FMI 3, DEF tank level sensor voltage above normal or open circuitΒΆ

Description

The measured tank level signal is above the normal operating range.

Possible causes are:

  • The DEF tank level sensor wiring is defective. (Shorted to high source or an open circuit.)
  • The DEF tank level 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 level 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 DEF tank level sensor operation. Measure the resistance over the level sensor. The resistance should be under 1MOhm.