Circuit DescriptionThe ECM calculates an aftertreatment diesel particulate filter flow resistance, using the aftertreatment diesel particulate filter differential pressure and calculated exhaust flow rate.

Component LocationThe aftertreatment diesel 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 only runs after successful completion of an active regeneration of the aftertreatment diesel particulate filter.

Conditions for Setting the Fault CodesThe Engine Control Module (ECM) calculated the aftertreatment diesel particulate filter flow resistance was too low after successful regeneration of the aftertreatment diesel particulate filter.

Action Taken When the Fault Code is ActiveThe ECM illuminates the amber CHECK ENGINE lamp and/or Malfunction Indicator Lamp (MIL) after the diagnostic fails on two consecutive trips.

Exhaust Gas Recirculation (EGR) valve operation will be disabled.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 CodeIt is necessary to use the “Reset All Faults” command in INSITE™ electronic service tool to clear this fault and extinguish the amber CHECK ENGINE lamp and/or Malfunction Indicator Lamp (MIL).

Shop TalkPossible causes of this fault code include:

A damaged aftertreatment diesel particulate filter differential pressure sensorMissing or malfunctioning aftertreatment diesel particulate filter differential pressure sensor tubesMalfunction aftertreatment diesel particulate filter.Reference the appropriate OEM wiring diagram when troubleshooting circuits that utilize wiring supplied by the OEM.

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