P2463

P2463-DIESEL PARTICULATE FILTER - SOOT ACCUMULATION

For complete wiring diagrams refer to Diagrams/Electrical.


Theory of Operation

The engine aftertreatment system monitors the soot load in the aftertreatment diesel particulate filter. Under normal operating conditions the aftertreatment diesel particulate filter is self-cleaning, where soot is converted to ash. Under light load operating conditions, the driver may be notified via the vehicle's EVIC message center that it may be necessary to modify the vehicle's driving routine/duty-cycle in order to allow the aftertreatment diesel particulate filter system to self clean. If the vehicle's EVIC message center notification is ignored, the vehicle will eventually derate and set a fault, requiring service. The soot load in the aftertreatment diesel particulate filter is estimated using the Exhaust Pressure Sensors and the calculated soot output of the engine. This fault code can be triggered if the application is not operating at a duty cycle high enough to actively regenerate the aftertreatment diesel particulate filter. This fault code indicates that the exhaust temperatures exiting the turbocharger are not high enough to actively regenerate the soot that is trapped in the aftertreatment diesel particulate filter. It may be necessary to increase the duty cycle of the application in order to prevent excessive soot accumulation and plugging of the aftertreatment diesel particulate filter. The ECM will set this fault if it detects that the aftertreatment diesel particulate filter is plugged or that the differential pressure across the diesel particulate filter is above the calibrated moderately severe threshold limit. The ECM will illuminates the MIL lamp immediately when the diagnostic runs and fails. The driver will be notified via the vehicle's EVIC Message Center. The ECM will also derate engine power output in an effort to protect the vehicle aftertreatment system. The ECM will turn off the MIL lamp immediately after the soot load has dropped below the Moderately Severe Level Threshold.

- When Monitored:

The diagnostic runs continuously when the engine is running.

- Set Condition:

The ECM will set this fault if it detects that the soot load in the diesel particulate filter is above the moderately severe level threshold limit.







Always perform the Pre-Diagnostic Troubleshooting procedure before proceeding.

Diagnostic Test


1. BASE ENGINE FAILURE

Check for base engine failures.

Check for potential cause of excessive soot generation in the engine.

Potential causes include a stuck open exhaust gas recirculation valve or a variable geometry turbocharger actuator that is not moving correctly, faulty fueling or oil intrusion into the aftertreatment/exhaust system.

Was a base engine failure found?

Yes

- Replace the failed base engine component causing the high black smoke levels. Replace the aftertreatment diesel particulate filter.
- Perform POWERTRAIN VERIFICATION TEST. Powertrain Verification Test

No

- Go To 2

2. CYLINDER MISFIRE

Start the engine.

Allow the engine to idle.

With the scan tool, read the Misfire counter status.

Is an engine misfire detected?

Yes

- Determine the cause of the engine misfire. Use scan tool Cylinder Cutout Test to isolate a failed injector. Replace the failed injector if necessary. Inspect the aftertreatment system for possible damage.
- Perform POWERTRAIN VERIFICATION TEST. Powertrain Verification Test

No

- Go To 3

3. EXHAUST TEMPERATURE SENSOR(S)

Turn the ignition off for 5 minutes.

Turn the ignition on.

With the scan tool check the temperature values of the Exhaust Temperature sensors.

Are the Exhaust temperature sensors reading within 6 degrees C of each other?

Yes

- Go To 4

No

- Replace the Exhaust Temperature Sensor that is out of context.
- Perform POWERTRAIN VERIFICATION TEST. Powertrain Verification Test

4. EXCESSIVE ENGINE OIL BEING INTRODUCED INTO THE AFTERTREATMENT SYSTEM FROM THE ENGINE

Remove the turbocharger outlet and inspect for signs of oil, fuel or moisture being introduced into the aftertreatment system from the engine.

Was engine oil, fuel or moisture found in the turbocharger exhaust outlet?

Yes

- Locate the cause of possible diesel fuel or engine oil being carried from the engine into the aftertreatment system. Inspect the aftertreatment for possible damage.
- Perform POWERTRAIN VERIFICATION TEST. Powertrain Verification Test

No

- Go To 5

5. REGENERATION OF AFTERTREATMENT

Technician should drive vehicle in response to level of EVIC Message Center Notification to facilitate Active Regeneration of the Aftertreatment Particulate Filter.

After the Active Regeneration of the Aftertreatment Particulate Filter, Clear DTC with Service Tool Is DTC P1451 still Active?

Yes

- Go To 6

No

- Repair completed, inform Owner of vehicle duty cycle requirements
- Perform POWERTRAIN VERIFICATION TEST. Powertrain Verification Test

6. AFTERTREATMENT DIESEL PARTICULATE FILTER

Remove and inspect the aftertreatment diesel particulate filter.

Does aftertreatment diesel particulate filter show evidence of failure?

Yes

- Replace the aftertreatment diesel particulate filter.
- Perform POWERTRAIN VERIFICATION TEST. Powertrain Verification Test

No

- Refer to the INTERMITTENT CONDITION Diagnostic Procedure. Intermittent Condition