Cummins ISB6.7 CM2350 (2013-17) Fault Code: 5691 PID: SPN: 6810 FMI: 11 Hybrid System OBD Related DTC Status- Root Cause Not Known. Unexpected data link communications between the ECM and the Hybrid system controller have occurred.

Cummins ISB6.7 CM2350 (2013-17) Fault Code: 5691 PID: SPN: 6810 FMI: 11 Hybrid System OBD Related DTC Status- Root Cause Not Known. Unexpected data link communications between the ECM and the Hybrid system controller have occurred.

Circuit Description
The system controller is the central control for the hybrid system. It handles hybrid system operations. It communicates to the engine electronic control module (ECM) via a J1939 data link connection.

Component Location
The location of the hybrid system controller varies by application and OEM. The controller will typically be mounted to the vehicle frame or suitable rigid bracket using capscrews. Refer to the OEM service manual for a more detailed component location description.

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

Conditions for Setting the Fault Codes
An unexpected data link message was sent from the Hybrid system controller to the ECM, and was unable to be interpreted.

Action Taken When the Fault Code is Active
The ECM illuminates the amber CHECK ENGINE lamp and/or the Malfunction Indicator Lamp (MIL) immediately when the diagnostic runs and fails.

Conditions for Clearing the Fault Code
1)To validate the repair, perform a key cycle, start the engine and let it idle for 1 minute.
2)The fault code status displayed by INSITE? electronic service tool will change to INACTIVE immediately after the diagnostic runs and passes.
3)The ECM will turn off the amber CHECK ENGINE lamp and/or MIL immediately after the diagnostic runs and passes.
4)The Reset All Faults command in INSITE? electronic service tool can be used to clear active and inactive faults.

Possible caused:
1)Incorrect data link termination resistance
2)Open or short circuit on J1939 data link
3)Malfunctioning engine ECM
4)Corrupted engine calibration
5)Malfunctioning Hybrid System Controller
6)Corrupted Hybrid System Controller calibration