Circuit DescriptionThe aftertreatment purge air actuator is used to purge the aftertreatment fuel injector system of fuel after active regeneration of the aftertreatment diesel particulate filter.

Component LocationThe aftertreatment fuel injector is installed in the exhaust system in the turbocharger adapter pipe. The aftertreatment fuel pressure sensor and aftertreatment fuel shutoff valve are installed in the shutoff valve manifold. The aftertreatment purge air actuator is located above the shutoff valve manifold.

Conditions for Running the DiagnosticsThis diagnostic runs when the aftertreatment purge air actuator is commanded OFF.

Conditions for Setting the Fault CodesThe Engine Control Module (ECM) detected an open circuit or short to ground in the aftertreatment purge air actuator circuit.

Action Taken When the Fault Code is ActiveThe ECM illuminates the amber CHECK ENGINE lamp and/or the Malfunction Indicator Lamp (MIL) immediately when the diagnostic runs and fails.Active regeneration of the aftertreatment diesel particulate filter will be disabled unitl the next key cycle.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, start the engine and perform the INSITE™ electronic service tool Aftertreatment Diesel Particulate Filter Regeneration Test.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 immediately after the diagnostic runs and passes.For On-Board Diagnostics (OBD) engines, the ECM will extinguish the Malfunction Indicator Lamp (MIL) after three consecutive trips where the diagnostic runs and passes.The Reset All Faults command in INSITE™ electronic service tool can be used to clear active and inactive faults, as well as extinguish the MIL for OBD applications.

Shop TalkPossible causes of this fault include:

An open circuit in the engine harness, connectors, or aftertreatment purge air actuatorA short circuit in the engine harness, connectors, or aftertreatment purge air actuatorA damaged aftertreatment purge air actuator.

Possible Cause:1) Aftertreatment Purge air actuator failure2) Engine harness3) ECM failure