Cummins ISC CM2150 (2007-09) Fault Code: 1921 PID: SID 324 SPN: 3251 FMI: 0 Aftertreatment Diesel Particulate Filter Differential Pressure - Data Valid But Above Normal Operating Range - Moderately Severe Level. The soot load of the aftertreatment diesel particulate filter has exceeded the recommended limits.

Verify the electronic control module (ECM) calibration is correct. Check the calibration revision history found on QuickServe™ Online for applicable fixes to the calibration stored in the ECM. If necessary, calibrate the ECM.

Note: This fault code indicates that the aftertreatment diesel particulate filter requires maintenance by performing a stationary regeneration procedure. This is a maintenance procedure only and is not covered by Cummins Inc. warranty.

Note: Repeated occurrences of this fault code may indicate the engine requires frequent regeneration. Refer to symptom tree t147 (Aftertreatment Diesel Particulate Filter-Excessive Automatic and/or Stationary Regeneration) to identify the cause of frequent regeneration.

Possible causes:

1)The engine has been operating in a light load condition that prevents exhaust temperatures from being high enough to actively regenerate the aftertreatment diesel particulate filter.
2)Possible engine failure that causes excessive black soot to be generated.
3)If Fault Code 2777 is active along with Fault Code 1921, this indicates that a regeneration inhibit message has been received by the engine ECM and that active regeneration of the aftertreatment diesel particulate filter was not permitted. Confirm that the OEM settings for the aftertreatment permit switch are configured correctly.
4)The aftertreatment diesel particulate filter can accumulate an excessive amount of ash in a short time period, due to excessive oil consumption or due to non-combustible elements such as, but not limited to, iron, potassium, or calcium contained in the fuel supply or additives.
The aftertreatment diesel particulate filter soot loading can be classified into four different stages. As the soot load increases, the aftertreatment diesel particulate filter lamp and the Cummins® CHECK ENGINE (Amber) or STOP ENGINE (Red) lamp will operate according to the table below. Inadequate temperature of the exhaust gases entering the aftertreatment system can be a cause of high soot loads in the aftertreatment diesel particulate filter. The duty cycle of the application will need to be increased in order to prevent excessive soot from accumulating in the filter.

Possible repairs:

1)Change the duty cycle of the application in order to increase the exhaust temperatures entering the aftertreatment system.