Circuit DescriptionThe engine aftertreatment system monitors for the presence of the aftertreatment diesel particulate filter. This diagnostic checks to make sure that the aftertreatment diesel particulate filter is present and functioning correctly.

Component LocationThe aftertreatment particulate filter is located in the exhaust system and is installed by the original equipment manufacturer (OEM). Refer to the OEM service manual.

Conditions for Running the DiagnosticsThis diagnostic runs when the engine is operating and exhaust flow is above a minimum level.

Conditions for Setting the Fault CodesThis diagnostic monitors the aftertreatment diesel particulate filter differential pressure sensor. When the differential pressure is below a minimum value and exhaust flow rate is above a minimum flow rate, the fault code is set.

Action Taken When the Fault Code is ActiveThe ECM will illuminate the amber CHECK ENGINE lamp immediately after the diagnostic runs and passes for two consecutive trips.Active and stationary regeneration of the diesel particulate filter will be disabled.The EGR valve will be closed.Engine torque will be reduced if the engine is operated for an extended period of time with this fault active.Conditions for Clearing the Fault CodeTo validate the repair using a Diagnostic Road Test, utilize a route that incorporates both stop-and-go city driving and steady state highway driving. It may be necessary to load the unit for certain diagnostics in the ECM to run.To validate the repair using a Chassis Dynamometer Test, utilize a routine that incorporates acceleration and motoring events, steady state highway operation, and load. This will simulate normal driving and allow the diagnostics in the ECM to run.The fault code status displayed by INSITE? electronic service tool will change to INACTIVE immediately after the diagnostic runs and passes.The ECM will turn off the amber CHECK ENGINE lamp after the diagnostic runs and passes.The ?Reset All Faults? command in INSITE? electronic service tool can be used to clear active and inactive faults.

Shop TalkPossible causes of this fault code include:

The aftertreatment diesel particulate filter has been removed from the vehicleThe aftertreatment diesel particulate filter is cracked or brokenThe aftertreatment diesel particulate filter differential tubes are installed incorrectly, broken, loose, or have been tampered withThe aftertreatment diesel particulate filter differential tubes are installed backwards.Reference the appropriate OEM wiring diagram when troubleshooting circuits that utilize wiring supplied by the OEM.

For intermittent power supply and data link communication issues with aftertreatment components, it is highly recommended that the OEM power distribution center fuses and relays be thoroughly checked for loose, missing, or intermittent connections.

Possible Cause:1) Aftertreatment DPF differential pressure sensor tubes failure2) Aftertreatment DPF differential pressure sensor failure3) ECM calibration