P2455

P2455-DIESEL PARTICULATE FILTER PRESSURE SENSOR A CIRCUIT HIGH





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

Theory of Operation

The Diesel Particulate Pressure Sensor (Exhaust Pressure Sensor 1/2) is used to detect the amount of soot and ash buildup inside the Diesel Particulate Filter. The ECM provides a 5-volt supply to the Exhaust Pressure Sensor 1/2 on the sensor supply circuit. The ECM also supplies a ground on the sensor return circuit. The Exhaust Pressure Sensor 1/2 provides a signal to the ECM on the Exhaust Pressure Sensor 1/2 Signal circuit. This sensor signal voltage changes based on the pressure differential across the aftertreatment Diesel Particulate Filter. The ECM illuminates the MIL lamp immediately when the diagnostic runs and fails. A default value is used for the aftertreatment Diesel Particulate Filter differential pressure reading. Active aftertreatment regeneration will be disabled. The ECM will turn off the MIL lamp immediately after the diagnostic runs and passes.

- When Monitored:
Key on.

- Set Condition:
The ECM detects that the Exhaust Pressure Sensor 1/2 Signal voltage is greater than Calibratable voltage for more than a calibratable duration.





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

1. ACTIVE DTC

NOTE: If there are any 5-volt supply DTCs present, repair those DTCs before proceeding with this test.

1. Turn the ignition on.
2. With the scan tool, record all Freeze frame data.
3. With the scan tool, erase DTCs.
4. Turn the ignition off for 30 seconds.
5. Turn the ignition on.
6. With the scan tool, read DTCs.

Did the DTC reset?

Yes

- Go To 2

No

- Refer to the INTERMITTENT CONDITION - DIESEL diagnostic procedure. Intermittent Condition Test

2. (K182) EXHAUST PRESSURE SENSOR 1/2 SIGNAL CIRCUIT SHORTED TO VOLTAGE




1. Turn the ignition off.
2. Disconnect the Exhaust Pressure Sensor 1/2 harness connector.

NOTE: Check connectors - Clean/repair as necessary.

3. Turn the ignition on.
4. Measure the voltage on the (K182) Exhaust Pressure Sensor 1/2 Signal circuit at the Exhaust Pressure Sensor 1/2 connector.

Is the voltage reading above 5.1 volts?

Yes

- Repair the short to voltage on the (K182) Exhaust Pressure Sensor 1/2 Signal circuit.
- Perform POWERTRAIN VERIFICATION TEST - 6.7L. Powertrain Verification Test

No

- Go To 3

3. (K182) EXHAUST PRESSURE SENSOR 1/2 SIGNAL CIRCUIT SHORTED TO THE (K854) 5-VOLT SUPPLY CIRCUIT




1. Turn the ignition off.
2. Disconnect the ECM C2 harness connector.
3. Measure the resistance between the (K182) Exhaust Pressure Sensor 1/2 Signal circuit and the (K854) 5-volt Supply circuit at the Exhaust Pressure Sensor 1/2 harness connector.

Is the resistance below 10k ohms?

Yes

- Repair the short between the (K182) Exhaust Pressure Sensor 1/2 Signal circuit and the (K854) 5-volt Supply circuit.
- Perform POWERTRAIN VERIFICATION TEST - 6.7L. Powertrain Verification Test

No

- Go To 4

4. (K182) EXHAUST PRESSURE SENSOR 1/2 SIGNAL CIRCUIT OPEN




1. Measure the resistance of the (K182) Exhaust Pressure Sensor 1/2 Signal circuit between the ECM C2 harness connector to the Exhaust Pressure Sensor 1/2 harness connector.

Is the resistance below 10.0 ohms?

Yes

- Repair the open or high resistance in the (K182) Exhaust Pressure Sensor 1/2 Signal circuit.
- Perform POWERTRAIN VERIFICATION TEST - 6.7L. Powertrain Verification Test

No

- Go To 5

5. (K400) APPS RETURN CIRCUIT OPEN




1. Measure the resistance of the (K400) APPS Return circuit between the ECM C2 harness connector to the Exhaust Pressure Sensor 1/2 harness connector.

Is the resistance below 10.0 ohms?

Yes

- Repair the open or high resistance in the (K400) APPS Return circuit.
- Perform POWERTRAIN VERIFICATION TEST - 6.7L.Powertrain Verification Test

No

- Go To 6

6. EXHAUST PRESSURE SENSOR 1/2
1. Reconnect the ECM C2 harness connector.
2. Ignition on, engine not running.
3. Leave the Exhaust Pressure Sensor 1/2 harness connector disconnected.
4. While monitoring the scan tool, connect a jumper between the (K182) Exhaust Pressure Sensor 1/2 Signal circuit and the (K400) APPS Return circuit in the Exhaust Pressure Sensor 1/2 harness connector.

Did the DTC P2454 Pressure Sensor Low become active?

Yes

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

No

- Replace the ECM.
- Perform POWERTRAIN VERIFICATION TEST - 6.7L. Powertrain Verification Test