P242F
P242F-DIESEL PARTICULATE FILTER RESTRICTION - ASH ACCUMULATION
For a complete wiring diagram, refer to the Wiring Information.
Theory of Operation
The engine after treatment system monitors the soot load in the Diesel Particulate Filter. Under normal operating conditions, the 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 Diesel Particulate Filter system to self clean. If the vehicle's EVIC message center notification is ignored, the vehicle will eventually de-rate the engine and set a DTC and MIL lamp, requiring service. The soot load in the Diesel Particulate Filter is estimated using the Exhaust Differential 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 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 Diesel Particulate Filter. It may be necessary to increase the duty cycle of the application in order to prevent plugging of the Diesel Particulate Filter. This fault will be triggered if the Powertrain Control Module (PCM) detects that the soot load of the Diesel Particulate Filter has surpassed the most severe level threshold. The PCM 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 Powertrain Control Module (PCM) will also initiate a de-rate of engine power output in an effort to protect the vehicle after treatment system. The PCM will turn off the MIL lamp immediately after the soot load in the Diesel Particulate Filter has dropped below the severe level threshold and the DTC has been cleared.
- When Monitored:
The diagnostic runs continuously when the engine is running.
- Set Condition:
The Powertrain Control Module (PCM) detects that the ash load of the Diesel Particulate Filter has surpassed the most severe level threshold.
Always perform the Pre-Diagnostic Troubleshooting procedure before proceeding. Pre-Diagnostic Troubleshooting Procedure.
1. INSPECT THE AFTERTREATMENT SYSTEM
NOTE: If there are any DTCs present for the Exhaust Temperature Sensors or Exhaust Differential Pressure Sensor, diagnose those DTCs before proceeding with this test procedure.
NOTE: DTC P242F is usually the result of a driveability or fuel system failure. This DTC indicates that the Diesel Particulate Filter may either be face plugged or filled with ash. If there are any other DTCs or driveability concerns present with this DTC, diagnose and repair those concerns before continuing with this test procedure. Not repairing the cause of the excess soot being generated will cause the Diesel Particulate Filter to fill with soot too often and fail prematurely.
1. Perform the AFTERTREATMENT INSPECTION GUIDELINE - 6.7L procedure. Initial Inspection and Diagnostic Overview
Was any internal damage found in the Diesel Particulate Filter?
Yes
- Replace the Diesel Particulate Filter and reset the regenerative timers with the scan tool. Remove and clean the EGR Valve. Procedures. Perform the CHECKING ENGINE MISFIRE / RUNS ROUGH / PERFORMANCE test procedure. Checking Engine Misfire / Runs Rough / Performance Test
- Perform the DIESEL AFTERTREATMENT VALIDATION - 6.7L. Component Tests and General Diagnostics
No
- Go To 2
2. VERIFY THE ESTIMATED SOOT LOAD
1. Ignition on, engine not running.
2. With the scan tool, navigate to Data Display and read the Estimated Soot Load.
Is the Estimated Soot Load Based on Delta Pressure above 37.0 grams (pick-up) 57.0 grams (cab chassis)?
Yes
- Go To 3
No
- Erase DTCs and reset the regenerative timers with the scan tool.
- Perform the DIESEL AFTERTREATMENT VALIDATION - 6.7L. Component Tests and General Diagnostics
3. CHECK FOR THE ESTIMATED SOOT LOAD ABOVE MAX SOOT LOAD
1. Ignition on, engine not running.
2. With the scan tool, navigate to Data Display and read the Estimated Soot Load.
Is the Estimated Soot Load Based on Delta Pressure above 75.0 grams (pick-up) 92.0 grams (cab chassis)?
Yes
- Replace the Diesel Particulate Filter.
- Perform the DIESEL AFTERTREATMENT VALIDATION - 6.7L. Component Tests and General Diagnostics
No
- Go To 4
4. STATIONERY REGENERATION
1. With the scan tool, erase DTCs, reset regenerative filter timers, and drive vehicle until P1451 resets (this will allow you to perform a stationary Desoot).
NOTE: The vehicle will not allow the Stationery Desoot to run if the P242F DTC sets. For this reason, test drive the vehicle as close to the shop as possible in order to get back to the shop before the P242F DTC can set.
2. Perform the scan tool initiated Stationary Desoot.
3. After the Stationary Desoot is completed, erase the DTCs with the scan tool.
4. Perform the DIESEL AFTERTREATMENT VALIDATION - 6.7L. Component Tests and General Diagnostics
Did a P1451, P2463, or P242F DTC set during the validation?
Yes
- Perform the CHECKING ENGINE MISFIRE / RUNS ROUGH / POOR PERFORMANCE test procedure. Checking Engine Misfire / Runs Rough / Performance Test
No
- Repair complete.