For 1990-2009 cars

### Diagnostic Instructions

• | Perform the Diagnostic System Check - Vehicle prior to using this diagnostic procedure.

• | Review Strategy Based Diagnosis for an overview of the diagnostic approach.

• | Diagnostic Procedure Instructions provides an overview of each diagnostic category.

### Circuit/System Description

If a vehicle has an active or inactive diesel particulate filter (DPF) related diagnostic trouble code (DTC) a scan tool can be used to initiate a controlled service mode DPF regeneration. This function assists in locating the DPF components requiring repair. The service regeneration mode is also the only way to regenerate the DPF when the soot mass level has increased past the maximum threshold. When the DPF soot mass level exceeds a calibrated value, the ECM will command power reduction and normal driving regeneration is inhibited. Performing a service regeneration will remove the power reduction command. The service regeneration mode ignores many of the abort conditions required for normal driving regeneration. The service regeneration mode is also useful to verify that repairs to the DPF system have been successful. DPF diagnostics are active during a service regeneration. Monitoring for DPF DTCs during the service regeneration will help determine if any issues are present. If any DTCs occur, repair the issue and rerun the service regeneration mode. During the service regeneration procedure, the tailpipe outlet temperature will be greater than 550°C (1,022°F). Use caution around the engine compartment, and exhaust system during the regeneration procedure.

### Reference Information

#### Scan Tool Reference

Control Module References for scan tool information

### Circuit/System Verification

1. Ignition OFF, verify the coolant is at the correct level.

⇒ | If the coolant is low, refer to Loss of Coolant for diagnosis of the cooling system.

2. Ignition ON, observe the scan tool diagnostic trouble code (DTC) information. Verify there are no DTCs set.

⇒ | If there are any DTCs set, refer to Diagnostic Trouble Code (DTC) List - Vehicle for further diagnosis.

3. Engine idling, verify there are no engine mechanical conditions.

⇒ | If there is a mechanical condition, refer to Symptoms - Engine Mechanical for further diagnosis.

4. Observe the scan tool DPF soot mass parameter. The parameter should be less than 5 grams.

### Circuit/System Testing

Caution: Tailpipe outlet exhaust temperatures will be greater than 550°C (1022°F) during service regeneration. In order to prevent personal injury or property damage from fire, or burns, perform the following:

1. Inspect and remove any debris from the exhaust system prior to service regeneration.
2. Do not connect any shop exhaust removal hoses to the vehicle tailpipe.
3. Park the vehicle outdoors with the hood open, away from walls or buildings.
4. Keep people, other vehicles, and combustible material away during service regeneration.
5. Do not leave the vehicle unattended.

Important:

• | The service regeneration procedure can be stopped at any time in an emergency by switching off the ignition, depressing the brake pedal, or with a scan tool. Depressing the brake pedal returns the engine to idle speed. The scan tool function allows the engine to slowly return to idle.

• | Oil changes may be necessary after running the service regeneration mode. Every time the service regeneration is run, the oil viscosity will be reduced. Change the engine oil after service regeneration if the oil life remaining is less than 80%. Also, if more than 3 service regenerations are run consecutively, change the engine oil regardless of the oil life remaining.

1. Inspect the DPF. Verify there is no soot leaking from the DPF.

⇒ | If soot is present, replace the DPF.

2. Select the DPF service regeneration in the scan tool output control menu.
3. Follow the corresponding instructions displayed on the screen of the scan tool.
4. After completing the DPF service regeneration, operate the engine at 1,500 RPM for 1 minute in order to let the exhaust cool evenly.
5. Ignition OFF, allow the engine to cool down.
6. Verify the coolant is at the correct level.

### Repair Instructions

Exhaust Particulate Filter Replacement

### Repair Verification

• | Ignition ON, observe the scan tool diagnostic trouble code (DTC) information. Verify there are no DTCs set.

⇒ | If there are any DTCs set, refer to Diagnostic Trouble Code (DTC) List - Vehicle for further diagnosis.

• | Engine idling, verify the scan tool DPF soot mass parameter is near 0 grams.

⇒ | If not within the specified range, repeat the service regeneration procedure.