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 purge air actuator is mounted on the left side of the engine above the aftertreatment fuel shutoff manifold.

Conditions for Running the DiagnosticsThis diagnostic runs during active regeneration of the aftertreatment diesel particulate filter.

Conditions for Setting the Fault CodesThe ECM detects that the aftertreatment fuel pressure is lower than a threshold when the aftertreatment purge air actuator is commanded on.

Action Taken When the Fault Code is ActiveThe ECM illuminates the amber CHECK ENGINE lamp and/or Malfunction Indicator Lamp (MIL) immediately when the diagnostic runs and fails. Active aftertreatment diesel particulate filter regeneration will be disabled until the next key cycle

Conditions for Clearing the Fault CodeTo validate the repair, perform INSITE? electronic service tool Aftertreatment Diesel Particulate Filter Regeneration Test. Once the temperatures in the aftertreatment are warm enough to inject diesel fuel into the exhaust, the diagnostic will 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.For On-Board Diagnostics (OBD) engines, the ECM will turn off the 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:

A stuck closed aftertreatment purge air actuatorMissing or leaking air supply line to the aftertreatment purge air actuatorMissing or leaking air supply line from the aftertreatment purge air actuator to the shutoff valve manifold.Reference the appropriate OEM wiring diagram when troubleshooting circuits that utilize wiring supplied by the OEM.

For intermittent power supply and datalink 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 purge air actuator failure2) ECM calibration