Circuit DescriptionThe aftertreatment system is monitored by temperature sensors that are located in the exhaust system. The aftertreatment diesel oxidation catalyst intake temperature sensor is located after the turbocharger outlet. The aftertreatment diesel particulate filter intake temperature sensor is located between the aftertreatment catalyst and the aftertreatment particulate filter. The aftertreatment diesel particulate filter outlet temperature sensor is located after the aftertreatment particulate filter. These sensors monitor the temperatures in the aftertreatment system and determine if the aftertreatment catalyst is missing.

Component LocationThe aftertreatment catalyst is located in the exhaust system. The location of the catalyst can vary depending on the original equipment manufacturer (OEM). Refer to the OEM service manual.

Conditions for Running the DiagnosticsThis diagnostic runs when the aftertreatment system is being actively regenerated to reduce soot in the aftertreatment diesel particulate filter. The diagnostic checks for a temperature increase across the catalyst during an active regeneration of the aftertreatment system to detect the presence of the catalyst.

Conditions for Setting the Fault CodesThe electronic control module (ECM) detects that the aftertreatment diesel oxidation catalyst intake temperature sensor and the aftertreatment diesel particulate filter intake temperature sensor are reading the same temperature during an active regeneration of the aftertreatment system.

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 on 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, perform 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 after the diagnostic runs and passes.For OBD engines, the ECM will turn off the MIL after 3 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 the MIL for OBD applications

Shop TalkThis fault code becomes active when the aftertreatment diesel oxidation catalyst intake and aftertreatment diesel particulate filter intake temperature sensors do not detect the presence of a catalyst in the aftertreatment system.

Possible causes of this fault code include:

Tampering with the catalyst systemRemoving the catalyst system from the vehicleA damaged catalyst.The type of diesel exhaust fluid tank temperature and level sensor used can vary depending on the vehicle OEM. As a result, the physical and/or electrical sensor configuration may vary slightly from what is shown in the troubleshooting and wiring diagram information.

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 Injector failure2) ECM calibration