P242F

P242F-DIESEL PARTICULATE FILTER RESTRICTION - ASH ACCUMULATION

For a complete wiring diagram, refer to the Wiring Information Electrical Diagrams.

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 vehicles driving routine 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 the engine and set a DTC and MIL lamp, requiring service. The soot load in the aftertreatment diesel particulate filter is estimated using the Exhaust Pressure Sensor 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 plugging of the aftertreatment Diesel Particulate Filter. This fault will be triggered if the Engine Control Module (ECM) detects that the soot load of the aftertreatment Diesel Particulate Filter has surpassed the most severe level threshold. The aftertreatment Diesel Particulate Filter needs to be replaced, do not regenerate this filter. The ECM will illuminate the MIL lamp immediately when the diagnostic runs and fails. The driver will be notified via the vehicle's EVIC Message Center (CATALYST FULL: SERVICE REQD). The ECM will also initiate a derate of 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 in the aftertreatment Diesel Particulate Filter has dropped below the severe level threshold (this should be accomplished through replacing the aftertreatment Diesel Particulate Filter) and the DTC has been cleared.

- When Monitored:
The diagnostic runs continuously when the engine is running.

- Set Condition:
The Engine Control Module (ECM) detects that the soot load of the aftertreatment Diesel Particulate Filter has surpassed the most severe level threshold. The aftertreatment Diesel Particulate Filter requires replacement.





Always perform the Pre-Diagnostic Troubleshooting procedure before proceeding. Pre-Diagnostic Troubleshooting Procedure.

1. OTHER DTCS
1. Ignition on, engine not running.
2. With the scan tool, read DTCs.

Are any other Misfire or Exhaust Gas Temperature/Pressure Sensor DTCs Active?

Yes

- Repair all other DTCs first.

No

- Go To 2

2. BASE ENGINE FAILURE
1. Check for base engine failures.
2. Check for potential cause of excessive soot generation in the engine.
3. Potential causes include a stuck open exhaust gas recirculation valve or a variable geometry turbocharger actuator that is not moving correctly.

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 the POWERTRAIN VERIFICATION TEST - 6.7L. Powertrain Verification Test.

No

- Go To 3

3. CYLINDER MISFIRE
1. Start the engine.
2. Allow the engine to idle.
3. 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 the POWERTRAIN VERIFICATION TEST - 6.7L. Powertrain Verification Test.

No

- Go To 4

4. EXHAUST TEMPERATURE SENSOR(S)
1. Turn the ignition off for five minutes.
2. Turn the ignition on.
3. With the scan tool check the temperature values of the Exhaust Gas Temperature Sensors.

Are the Exhaust temperature sensors reading within 25°C (77°F) of each other?

Yes

- Go To 5

No

- Replace the Exhaust Temperature Sensor that is out range.
- Perform the POWERTRAIN VERIFICATION TEST - 6.7L. Powertrain Verification Test.

5. EXCESSIVE ENGINE OIL BEING INTRODUCED INTO THE AFTERTREATMENT SYSTEM FROM THE ENGINE
1. 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 the POWERTRAIN VERIFICATION TEST - 6.7L. Powertrain Verification Test.

No

- Go To 6

6. AFTERTREATMENT DIESEL PARTICULATE FILTER
1. Remove and inspect the aftertreatment diesel particulate filter.

Does aftertreatment diesel particulate filter show evidence of failure?

Yes

- Replace the aftertreatment Diesel Particulate Filter. A mobile desoot is not required after replacement of the aftertreatment Diesel Particulate Filter.
- Reset the Regenerative filter timers. Located under miscellaneous functions.
- Perform the POWERTRAIN VERIFICATION TEST - 6.7L. Powertrain Verification Test.

No

- Perform the INTERMITTENT CONDITION diagnostic procedure. Intermittent Condition Test.