4.2.188. SPN 520201, FMI 19, Bus off Engine CAN (1M)

Description

EEM4 system can not be able to communicate through CAN bus.(1M)

Possible causes are:

  • Short circuit or defective wiring on CAN bus.
  • A poor connection.

Reaction in EEM

The FC is stored and the warning lamp is activated. The CAN message indicates active fault.

NOTE: This doesn’t have affects for engine normal functions beacause Engine CAN is only used for R&D.

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 CAN bus for a short circuit or an open load on the CAN bus.
  • Check the ECU connectors and the contact surfaces of the connector pins (possible oxidation).
  • Check the ECU operation with another EEM4 controller. If the system is functional and the fault is not active with the replacement ECU, then the original ECU is defective.