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.

Posted by PerDiezel Solutions on January 20, 2026

Circuit Description
The aftertreatment diesel exhaust fluid line heater relay provides the power supply to line heaters 1, 2, and 3. It is controlled by the aftertreatment diesel exhaust fluid controller.

Component Location
The aftertreatment diesel exhaust fluid line heater relay location is OEM dependent. Refer to the OEM troubleshooting manual for more information.

Conditions for Running the Diagnostics
This diagnostic runs continuously when the engine is running and diesel exhaust fluid line heating is not being commanded.

Conditions for Setting the Fault Codes
Battery voltage has been detected at the diesel exhaust fluid line heaters when the line heater relay is commanded off.

Action Taken When the Fault Code is Active
-The ECM illuminates the amber CHECK ENGINE lamp and/or the MIL immediately when the diagnostic runs and fails.
-Diesel exhaust fluid line heating will be disabled.

Conditions for Clearing the Fault Code
-Upon completion of the repair, a key cycle is required in order to get the diagnostic to run again and make the fault go inactive.
-The ECM will turn off the amber CHECK ENGINE lamp immediately after the diagnostic runs and passes.
-The ECM will turn off the MIL after 3 consecutive ignition cycles that the diagnostic runs and passes.
-This fault code and malfunction indicator lamp (MIL) can also be cleared with INSITE™ electronic service tool.

Possible Causes
-Switch side of line heater relay stuck closed
-Short to battery voltage in the wire between the relay and line heater elements.

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.

Cummins ISB4.5 CM2150 Fault Code: 3651 PID: SID 254 SPN: 3031 FMI: 18 Aftertreatment Diesel Exhaust Fluid Tank Temperature – Data Valid But Below Normal Operating Range – Moderately Severe Level.

Cummins ISB4.5 CM2150 Fault Code: 3648 PID: SID 254 SPN: 5480 FMI: 16 Aftertreatment Diesel Exhaust Fluid Controller Temperature – Data Valid But Above Normal Operating Range – Moderately Severe Level.

Cummins ISB4.5 CM2150 Fault Code: 3616 PID: SPN: 2633 FMI: 7 Engine VGT Nozzle Position – Mechanical System Not Responding or Out of Adjustment.

WARNING!