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P2002




DTC P2002

Diagnostic Instructions

* Perform the Diagnostic System Check - Vehicle (Diagnostic System Check - Vehicle) prior to using this diagnostic procedure.
* Review Strategy Based Diagnosis (Strategy Based Diagnosis) for an overview of the diagnostic approach.
* Diagnostic Procedure Instructions (Diagnostic Procedure Instructions)provide an overview of each diagnostic category.

DTC Descriptor
DTC P2002
- Diesel Particulate Filter Efficiency

Circuit/System Description

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.

Conditions for Running the DTC

* DTCs P0101, P2228, P2229, P2453, P2454, and P2455 are not set.
* The engine speed is greater than 600 RPM.
* The ambient air temperature is greater than -7°C (19°F).
* The BARO is greater than 75 kPa (11 psi).
* The engine run time is greater than 10 s.
* A regeneration event must be complete.
* The DPF inlet and outlet temperatures are between 100-400°C (212-752°F).
* The time since last DPF regeneration is less than 20 minutes.
* The distance since last DPF regeneration is less than 48 km (30 mi).
* The Soot Mass is less than 44 grams.
* DTC P2002 runs once when the above conditions are met.

Conditions for Setting the DTC

The ECM detects that the particulate filter has degraded below a calibrated threshold for greater than 20 s.

Action Taken When the DTC Sets

DTC P2002 is a Type B DTC.

Conditions for Clearing the DTC

DTC P2002 is a Type B DTC.

Reference Information
Schematic Reference

Engine Controls Schematics ([1][2]Electrical Diagrams)
Connector End View Reference

Component Connector End Views (Connector End Views By Name)
Description and Operation

Exhaust Aftertreatment System Description (Emission Control Systems)
Electrical Information Reference

* Circuit Testing (Circuit Testing)
* Connector Repairs (Connector Repairs)
* Testing for Intermittent Conditions and Poor Connections (Testing for Intermittent Conditions and Poor Connections)
* Wiring Repairs (Wiring Repairs)

DTC Type Reference

Powertrain Diagnostic Trouble Code (DTC) Type Definitions (Powertrain Diagnostic Trouble Code (DTC) Type Definitions)
Scan Tool Reference

Control Module References (Programming and Relearning)for scan tool information

Circuit/System Verification

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

• If a DTC is set, refer to Diagnostic Trouble Code (DTC) List - Vehicle (Diagnostic Trouble Code (DTC) List - Vehicle) for further diagnosis.

2. Engine idling, perform the following:

1. Engine at operating temperature.
2. 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 s, 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.

3. Verify the following conditions do not exist with the exhaust and DPF system:

* Any damaged components
* Leaks in the Exhaust system -Refer to Exhaust Leakage (Exhaust Leakage)
* 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 B154 exhaust pressure differential sensor lines-The smaller line connects to the rear of the exhaust particulate filter and the smaller port of the exhaust pressure sensor.
* Completely restricted differential pressure sensor lines.

• If a condition is found, repair as necessary.

4. Verify the following conditions do not exist with the air induction system:

* Restrictions in the air induction system and the turbocharger system
* Leaks in the intake air ducts and the turbocharger ducts. Perform the Induction System Smoke Test in Charge Air Cooler Diagnosis Charge Air Cooler Diagnosis.
* Cracked or damaged B75B MAF sensor housing
* A skewed, stuck in range, or slow responding MAF sensor. Inspect the MAF sensor for contamination. Refer to DTC P0101 (P0101).
* 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.

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

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

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

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

7. If all components test normal, replace the diesel particulate filter.

Repair Instructions

Perform the Diagnostic Repair Verification (Verification Tests) after completing the repair.

* Exhaust Particulate Filter Replacement Service and Repair

Note: This procedure is not necessary if the SCR/DPF was replaced.

* Perform the scan tool Diesel Particulate Filter (DPF) Regeneration Enable (Diesel Particulate Filter (DPF) Regeneration Enable) procedure if the scan tool DPF Soot Mass is less than 30 g. If the scan tool DPF Soot Mass is 30 g or greater, perform the Diesel Particulate Filter (DPF) Service Regeneration (Diesel Particulate Filter (DPF) Service Regeneration) procedure. After completing the service regeneration, perform the following to verify the diagnostic passed:

1. The transmission is in park or neutral.
2. Increase the engine speed to wide open throttle for 30 s.
3. Release the accelerator pedal.
4. Observe the DTC information with a scan tool. DTC P2002 should not be set.

• If a DTC set, a condition still exists.

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