Cummins ISB4.5 CM2150 Fault Code: 3736 PID: SID 254 SPN: 3360 FMI: 11 Aftertreatment Diesel Exhaust Fluid Controller – Root Cause Not Known.

Posted by PerDiezel Solutions on January 20, 2026

Circuit Description
The aftertreatment diesel exhaust fluid controller is the central control for the SCR diesel exhaust fluid dosing system, and handles the dosing activity, tank level sensing, tank temperature sensing, line heating, and tank heating. It communicates to the engine via ECM via a J1939 data link connection.

Component Location
The location of the aftertreatment diesel exhaust fluid controller varies by application and OEM. The controller will typically be mounted to the vehicle frame or suitable rigid bracket using 3 or 4 capscrews. Refer to the OEM service manual for a more detailed component location description.

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

Conditions for Setting the Fault Codes
An unexpected data link message was sent from the ECM to the diesel exhaust fluid controller, 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.
-Diesel exhaust fluid injection into the aftertreatment system is disabled.

Conditions for Clearing the Fault Code
-This fault code cannot be cleared with INSITE™ electronic service tool.
-This fault code will go inactive immediately when normal communication between the ECM and diesel exhaust fluid controller are restored.
-To validate the repair, start the engine and let it idle for 1 minute.
-The ECM will turn off the amber CHECK ENGINE lamp and/or MIL immediately after the diagnostic runs and passes.
-Use INSITE™ electronic service tool to verify the fault code is inactive.
-The inactive fault code will be cleared from the memory after 9600 hours of engine operation without an occurrence again.

Possible Causes
-Incorrect data link termination resistance
-Open or short circuit on J1939 data link
-Malfunctioning engine ECM
-Corrupted engine calibration
-Malfunctioning diesel exhaust fluid controller
-Corrupted diesel exhaust fluid controller calibration

Cummins ISB4.5 CM2150 Fault Code: 3735 PID: SPN: 2884 FMI: 9 Engine Auxiliary Governor Switch – Abnormal Update Rate.

Cummins ISB4.5 CM2150 Fault Code: 3731 PID: SPN: 5110 FMI: 9 Instrument Cluster Control Module – Abnormal Update Rate.

Cummins ISB4.5 CM2150 Fault Code: 3713 PID: SID 254 SPN: 5491 FMI: 7 Aftertreatment Diesel Exhaust Fluid Line Heater Relay – Mechanical system not responding or out of adjustment.

Cummins ISB4.5 CM2150 Fault Code: 3697 PID: SID 254 SPN: 630 FMI: 12 Engine Control Module Calibration Memory – Bad Intelligent Device or Component.

Cummins ISB4.5 CM2150 Fault Code: 3681 PID: 411 SPN: 3228 FMI: 0 Aftertreatment outlet NOx sensor power supply – Data erratic, intermittent, or incorrect.

Cummins ISB4.5 CM2150 Fault Code: 3679 PID: SPN: 3361 FMI: 11 Aftertreatment Diesel Exhaust Fluid Dosing Unit – Root Cause Not Known.

WARNING!