P244A

P244A-DIESEL PARTICULATE FILTER DIFFERENTIAL PRESSURE TOO LOW

Theory of Operation

This diagnostic checks to make sure that the after treatment Diesel Particulate Filter is present and functioning correctly. The Engine Control Module (ECM) uses the Exhaust Pressure Sensor to monitor the pressure differential through the after treatment Diesel Particulate Filter. The ECM will set the fault if it detects that the after treatment diesel particulate filter is not present in the after treatment/exhaust system. This DTC is a two trip fault. Active regeneration of the after treatment Diesel Particulate Filter will be disabled. The ECM will turn off the MIL lamp immediately after the diagnostic runs and passes.

- When Monitored:
This diagnostic runs when the engine is running, but not during active regeneration of the after treatment Diesel Particulate Filter.

- Set Condition:
The Engine Control Module (ECM) will set the fault if it detects that the after treatment diesel particulate filter is not present in the after treatment/exhaust system.





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

1. VISUAL INSPECTION
1. Inspect that the after treatment Diesel Particulate Filter has not been tampered with or removed.

Tampering or removal of the after treatment system has been detected?

Yes

- Install the correct after treatment system for the vehicle.
- Perform the POWERTRAIN VERIFICATION TEST - 6.7L. Powertrain Verification Test.

No

- Go To 2

2. AFTER TREATMENT DIESEL PARTICULATE FILTER DIFFERENTIAL TUBES ARE REVERSED
1. Start the engine.
2. With the scan tool, monitor the Exhaust Pressure Sensor delta pressure reading.
3. The delta pressure should have a positive pressure reading. A negative reading indicates the hoses are reversed.

Is the Exhaust Pressure Sensor reading a positive value?

Yes

- Go To 3

No

- Reverse the Exhaust Pressure Sensor hoses.
- Perform the POWERTRAIN VERIFICATION TEST - 6.7L. Powertrain Verification Test.

3. EXHAUST SYSTEM LEAK
1. Turn the ignition off.
2. Perform the CHECKING THE EXHAUST SYSTEM FOR LEAKS test procedure. Checking the Exhaust System For Leaks.

Were any exhaust leaks found?

Yes

- Repair the Exhaust System leak.
- Perform the POWERTRAIN VERIFICATION TEST - 6.7L. Powertrain Verification Test.

No

- Go To 4

4. EXHAUST PRESSURE SENSOR
1. Visually inspect the inside of the tailpipe for excessive soot buildup.

Is there excessive soot buildup inside tailpipe?

Yes

- Go To 5

No

- Replace the Exhaust Pressure Sensor.
- Perform the POWERTRAIN VERIFICATION TEST - 6.7L. Powertrain Verification Test.

5. AFTER TREATMENT DIESEL PARTICULATE FILTER
1. Remove the Diesel Particulate Filter.
2. Inspect for damage inside of the Diesel Particulate Filter.

Is filter cracked or broken internally?

Yes

- Replace the Diesel Particulate Filter.
- Perform the POWERTRAIN VERIFICATION TEST - 6.7L. Powertrain Verification Test.

No

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