The diesel particulate filter (DPF) differential pressure sensor is established to detect the difference in pressure in DPF. The engine control module (ECM) always detects differential pressure in DPF with the DPF differential pressure sensor installed in the DPF front and back, and detects quantity of sedimentation of PM.

The ECM detects that the diesel particulate filter differential pressure status is more than a predetermined range of calculated differential pressure value.

DTC P244B is a Type A DTC.

DTC P244B is a Type A DTC.

Inspect for any recent engine mechanical repairs. An incorrectly installed DPF differential pressure sensor will cause this DTC to set.

Schematic Reference

Engine Controls Schematics

Connector End View Reference

Electrical Information Reference

DTC Type Reference

Powertrain Diagnostic Trouble Code (DTC) Type Definitions

Scan Tool Reference

Important: If DTC P0079, P0080, P0102, P0103, P02E7, P02E8, P0409, P0652, P0653, P2032, P2033, P2454 and P2455 are set, test and repair those DTCs first.

Verify the integrity of the engine exhaust system by inspecting for the following conditions:

Important: You must perform Circuit/System Verification before proceeding with Circuit/System Testing.

1. Ignition OFF, inspect the DPF differential pressure sensor and pressure hose.

⇒	If detect the clogged condition for DPF differential pressure sensor and pressure hose, repair or replace the DPF differential pressure sensor and pressure hose.

2. Ignition ON for longer than 30 seconds, then ignition OFF for longer than 15 seconds, learning the zero position of DPF differential pressure.
3. Perform the DPF regeneration.
4. Clean the DPF filter with an Ash Cleaner.
5. Start the engine and operate the vehicle within the Conditions for Running the DTC. You may also operate the vehicle within the conditions that you observed from the freeze Frame/Failure Records.

⇒	If detect the DTC, replace the ECM.

6. Disconnect the DPF differential pressure sensor.
7. Turn ON the ignition with the engine OFF.
8. Disconnect the DPF differential pressure sensor connector and probe the signal circuit with a test lamp connected to ground.

⇒	If the test lamp illuminates, test the signal circuit for a short to voltage. If the circuits test normal, replace the ECM.

9. Connect a DMM between the DPF differential pressure sensor 5-volt reference circuit and ground, and measure the voltage.

⇒	If the voltage is not 4.9-5.1 volts, test for an open in the 5-volt reference circuit. If the circuits test normal, replace the ECM.

10. Connect a DMM between the DPF differential pressure sensor signal circuit and ground at the ECM side connector. Connect the terminal between the DPF differential pressure sensor signal circuit and the low reference circuit at the sensor side connector, and observe the resistance with a DMM DPF differential pressure parameter with a scan tool

⇒	If resistance is more than 0.2 ohms, the fuel pressure goes to-27 kPa , replace the DPF differential pressure sensor.

⇒	If resistance is more than 0.2 ohms, fuel pressure does not go to 112 kPa, test the signal circuit and the low reference circuit for an open.

⇒	If the circuits test normal, replace the ECM.

11. Ignition OFF, inspect the DPF filter.

⇒	If detect the broken, clogged condition, melt of filter for DPF filter, replace the DPF filter.

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.