P244A

P244A-DIESEL PARTICULATE FILTER DIFFERENTIAL PRESSURE TOO LOW

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. The ECM monitors for the presence of the aftertreatment particulate filter. This diagnostic checks to make sure that the aftertreatment particulate trap is present and functioning correctly. The ECM monitors the presence of the aftertreatment diesel particulate filter via interpretation of data received from the Exhaust Pressure Sensors, which monitors pressure differential across the aftertreatment diesel particulate filter. The ECM will set the fault if it detects that the aftertreatment diesel particulate filter is not present in the aftertreatment/exhaust system. The ECM will illuminate the MIL lamp immediately when the diagnostic runs and fails. 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 aftertreatment particulate filter.

- Set Condition:

The ECM will set the fault if it detects that the aftertreatment diesel particulate filter is not present in the aftertreatment/exhaust system.







Always perform the Pre-Diagnostic Troubleshooting procedure before proceeding.

Diagnostic Test


1. OTHER DTCS

Ignition on, engine not running.

With the scan tool, read DTC's.

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

Yes

- Repair all other DTCs before continuing.

No

- Go To 2

2. EXHAUST PRESSURE SENSOR TUBES

Turn the ignition off.

Inspect the Exhaust Pressure Sensor tubes for the following:

Leaks or cracks in the differential pressure tubes.

Loose fittings differential pressure tubes.

Missing or broken differential pressure sensor tubes.

Plugged or Reversed differential pressure sensor tubes.

Exhaust Pressure Sensor tubes are in good condition and installed properly?

Yes

- Go To 3

No

- Repair of replace the Exhaust Pressure Sensor tubes.
- Go To 4

3. AFTERTREATMENT DIESEL PARTICULATE FILTER

Inspect the aftertreatment diesel particulate filter. Inspect for evidence of tampering or removal of the diesel particulate.

Tampering or removal of the aftertreatment system has been detected?

Yes

- Install the correct aftertreatment system for the vehicle.
- Go To 4

No

- Go To 4

4. P244A INACTIVE

Ignition on, engine not running.

With the scan tool, read DTC's.

Check for active fault codes.

Is fault code P244A inactive?

Yes

- Repair complete. Erase DTC's.
- Perform POWERTRAIN VERIFICATION TEST. Powertrain Verification Test

No

- Go To 1