Cummins ISB4.5 CM2150 Fault Code: 291 PID: SPN: 625 FMI: 9 Proprietary Data Link Error (OEM/Vehicle Data Link) – Abnormal Update Rate.

Circuit Description
The immobilizer anti-theft device is connected to the primary engine electronic control module (ECM) through a J1939 data link network.

Messages sent from the immobilizer anti-theft device are received by the Cummins® ECM and are used to control the anti-theft features. The Cummins® ECM and immobilizer anti-theft device must be configured properly so that proper operation of the multiplexed components will occur.

Component Location
The J1939 data link wiring and location of OEM installed J1939 devices varies by OEM. The immobilizer anti-theft device is installed by the OEM. Refer to the OEM service manual for location.

Conditions for Running the Diagnostics
This diagnostic runs continuously when the keyswitch is in the ON position.

Conditions for Setting the Fault Codes
The ECM is not able to communicate with the immobilizer anti-theft system via the J1939 data link.

Action Taken When the Fault Code is Active
The ECM illuminates the appropriate amber or red fault lamp when the diagnostic runs and fails.

Conditions for Clearing the Fault Code
The ECM turns off the appropriate fault lamp when the diagnostic runs and passes.

Possible Causes

-When the ECM is set up properly to receive information from an immobilizer anti-theft device, but the immobilizer anti-theft device could possibly not be transmitting the message for that component. This can be caused when a multiplexed component is enabled in the Cummins® ECM, but the immobilizer anti-theft device source address of the VECU transmitting the component message is incorrect in the Cummins® ECM, or the immobilizer anti-theft device is not set up to transmit the multiplexed component message.
-This fault can be caused by a malfunctioning J1939 data link connection between the immobilizer anti-theft device and Cummins® ECM, a malfunctioning connection between the component and the immobilizer anti-theft device, malfunctioning immobilizer anti-theft device or malfunctioning Cummins® ECM. It could be necessary to contact the OEM for proper multiplexing configuration.