P2455

P2455-DIESEL PARTICULATE FILTER PRESSURE SENSOR A CIRCUIT HIGH





For a complete wiring diagram, refer to the Wiring Information.

Theory of Operation

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

- When Monitored:
Key on.

- Set Condition:
The Powertrain Control Module (PCM) detects that the Exhaust Pressure Sensor 1/2 Signal voltage is greater than calibrated voltage for more than a calibrated 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 75 seconds.
5. Turn the ignition on.
6. With the scan tool, read DTCs.

Did the DTC reset?

Yes

- Go To 2

No

- Perform the INTERMITTENT CONDITION - 6.7L diagnostic procedure. Intermittent Condition Test

2. CHECK THE (K182) EXHAUST PRESSURE SENSOR 1/2 SIGNAL CIRCUIT FOR A SHORT 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 (K182) Exhaust Pressure Sensor 1/2 Signal circuit for a short to voltage.
- Perform the POWERTRAIN VERIFICATION TEST - 6.7L. Powertrain Verification Test.

No

- Go To 3

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




1. Turn the ignition off.
2. Disconnect the PCM 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 the POWERTRAIN VERIFICATION TEST - 6.7L. Powertrain Verification Test.

No

- Go To 4

4. CHECK THE (K182) EXHAUST PRESSURE SENSOR 1/2 SIGNAL CIRCUIT FOR AN OPEN/HIGH RESISTANCE
1. Measure the resistance of the (K182) Exhaust Pressure Sensor 1/2 Signal circuit between the PCM C2 harness connector to the Exhaust Pressure Sensor 1/2 harness connector.

Is the resistance below 5.0 Ohms?

Yes

- Go To 5

No

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

5. CHECK THE (K400) APPS RETURN CIRCUIT FOR AN OPEN/HIGH RESISTANCE
1. Measure the resistance of the (K400) APPS Return circuit between the PCM C2 harness connector to the Exhaust Pressure Sensor 1/2 harness connector.

Is the resistance below 5.0 Ohms?

Yes

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

No

- Go To 6

6. CHECK THE EXHAUST PRESSURE SENSOR
1. Reconnect the PCM 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 the POWERTRAIN VERIFICATION TEST - 6.7L. Powertrain Verification Test.

No

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