3.2.85. SPN 171, FMI 19, Ambient temperature CAN signal missingΒΆ

Description

The EEM4 system was not able to receive valid ambient temperature via CAN.

Possible causes are:

  • The ambient sensor is defective.
  • The sensor wiring is defective.
  • The CAN message configuration is invalid.

Reaction in EEM

The FC is stored and the warning lamp is activated. 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:

  • Check the ambient temperature sensor wiring, the connectors and the contact surfaces of the connector pins (possible oxidation).
  • Check the operation with another ambient temperature sensor to see if the ambient temperature sensor is defective.
  • Check if a valid message (Ambient conditions PGN 64923) can be found from the CAN bus.