The particulates in the exhaust gases are collected by the diesel particulate filter (DPF). When the filter becomes saturated with particulates, they are oxidized by a regeneration process. The regeneration process increases the exhaust gas temperature, heating the diesel oxidation catalyst (DOC), and the DPF. The accumulated particulate matter in the DPF will then be safely converted to harmless gases and the DPF will then be clean and ready to filter additional particulate matter.

The engine control module (ECM) monitors the system with inputs from two exhaust gas temperature (EGT) sensors 1 and 2 and a differential pressure sensor. This diesel particulate filter diagnostic provides a means for monitoring the exhaust particulate filter efficiency. The resistive exhaust flow is monitored to determine if a DPF substrate is missing or a defined DPF failure has occurred. The resistive exhaust flow is calculated from mass air flow and DPF differential pressure. This diagnostic will run after a successful regeneration event has completed. This includes a successful service regeneration event.

The ECM detects that the particulate filter has degraded below a calibrated threshold for greater than 30 seconds.

DTC P2002 is a Type B DTC.

DTC P2002 is a Type B DTC.

Schematic Reference

Engine Controls Schematics

Connector End View Reference

Component Connector End Views

Description and Operation

Diesel Particulate Filter (DPF) System Description

Electrical Information Reference

DTC Type Reference

Powertrain Diagnostic Trouble Code (DTC) Type Definitions

Scan Tool Reference

Control Module References for scan tool information

1. Verify that DTCs P003A, P0047, P0048, P0101, P0201-P0208, P0234, P0299, P02A1, P02A5, P02AD, P02B1, P02B5, P02B9, P029D, P0300-P0308, P0401, P0402, P046C, P0545, P0546, P2032, or P2033 are not set.

⇒	If any of the DTCs are set, refer to Diagnostic Trouble Code (DTC) List - Vehicle.

2. Verify that leaks do not exist in the exhaust system. Refer to Exhaust Leakage.
3. Engine running at idle, perform the following:

3.1.	Engine coolant temperature greater than 80°C (176°F).

3.2.	Command the EGR solenoid with a scan tool to 35 percent.

3.3.

Perform several accelerator pedal sweeps by rapidly depressing the accelerator pedal to wide open throttle (WOT) and returning the pedal to the at rest position, allowing the engine to return to idle speed for 5 seconds, while observing the exhaust from the tailpipe. There should be very light or no smoke visible from the tailpipe.

⇒	If a heavy black smoke is observed from the vehicles tailpipe, replace the particulate filter assembly.

Important: Perform the Repair Verification after completing the Circuit/System Testing.

1. Verify the integrity of the entire exhaust system by visually inspecting for the following conditions:

•	Any damaged components

•	Improper installation--The exhaust differential pressure lines should have a continuous downward gradient, without sharp kinks, from the differential pressure sensor to the particulate filter.

•	Improperly routed exhaust differential pressure sensor lines--The smaller line connects to the front of the exhaust particulate filter and the smaller port of the exhaust pressure sensor.

•	Completely restricted differential pressure sensor lines.

2. Verify the integrity of the entire air induction system by inspecting for the following conditions:

•	Restrictions in the air induction system and the turbocharger system

•	Leaks in the intake air ducts and the turbocharger ducts

•	Cracked or damaged MAF sensor housing

•	Inspect for a dirty air filter element

•	Debris blocking the air sensing filaments of the MAF sensor

⇒	If a condition is found, repair as necessary.

3. Test the charge air cooler system for leaks. Perform the Full System Air Leak Test in Charge Air Cooler Diagnosis.

⇒	If a charge air cooler leak is found, repair as necessary.

4. Test the engine air induction system for leaks. Perform the Induction System Smoke Test in Charge Air Cooler Diagnosis.

⇒	If an induction air leak is found, repair as necessary.

5. If the air intake system, exhaust system, DPF components, and the charge air cooler test normal, replace the particulate filter.

1. Install any components or connectors that have been removed or replaced during diagnosis.
2. Perform any adjustment, programming, or setup procedures that are required when a component or module is removed or replaced.
3. Clear the DTCs.
4. Turn OFF the ignition for 90 seconds.
5. Duplicate the Conditions for Running the DTC and use the freeze Frame/Failure Records, if applicable, in order to verify the DTC does not reset. If the DTC resets or another DTC is present, refer to the Diagnostic Trouble Code (DTC) List - Vehicle and perform the appropriate diagnostic procedure.
6. Perform the Diesel Particulate Filter (DPF) Regeneration Enable.