P2455

P2455-DIESEL PARTICULATE FILTER PRESSURE SENSOR A CIRCUIT HIGH





For a complete wiring diagram Refer to Diagrams/Electrical.

Theory of Operation


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 provides a signal to the ECM on the Exhaust Pressure Sensor 1/2 Signal circuit. This sensor signal voltage changes based on the differential pressure across the aftertreatment diesel particulate filter. The ECM detects that the Exhaust Pressure Sensor 1/2 signal voltage is greater than a calibratable voltage for more than a calibratable duration. 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. Initial Inspection and Diagnostic Overview


Diagnostic Test


1. EXHAUST PRESSURE SENSOR 1/2
Turn the ignition off.
Visually inspect the Exhaust Pressure Sensor 1/2 and harness.
Disconnect the Exhaust Pressure Sensor 1/2 harness connector.

NOTE: Check connectors - Clean/repair as necessary.

Measure the resistance of the Exhaust Pressure Sensor 1/2.
Is the resistance between 300 and 90k ohms?

Yes


- Go To 2


No


- Replace the Exhaust Pressure Sensor 1/2.
- Perform POWERTRAIN VERIFICATION TEST - 6.7L. Powertrain Verification Test



2. P2455 INACTIVE
Reconnect Exhaust Pressure Sensor 1/2 harness connector.
Ignition on, engine not running.
With the scan tool, read DTCs.
Is the P2455 inactive?

Yes


- Refer to the INTERMITTENT CONDITION - DIESEL Diagnostic Procedure. Intermittent Condition


No


- Go To 3



3. (K182) EXHAUST PRESSURE SENSOR 1/2 SIGNAL CIRCUIT SHORTED TO VOLTAGE
Turn the ignition off.
Disconnect the C2 ECM harness connector.

NOTE: Check connectors - Clean/repair as necessary.

Turn the ignition on.
Measure the voltage on the (K182) Exhaust Pressure Sensor 1/2 Signal circuit at the sensor connector.
Is there any voltage present?

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 4



4. (K182) EXHAUST PRESSURE SENSOR 1/2 SIGNAL CIRCUIT OPEN
Turn the ignition off.
Measure the resistance of the (K182) Exhaust Pressure Sensor 1/2 Signal circuit from the ECM harness connector to the Exhaust Pressure Sensor 1/2 harness connector.
Is the resistance above 5.0 ohms?

Yes


- Repair the excessive 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
Measure the resistance of the (K400) APPS Return circuit from the C2 ECM harness connector to the Exhaust Pressure Sensor 1/2 harness connector.
Is the resistance above 5.0 ohms?

Yes


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


No


- Go To 6



6. (K182) EXHAUST PRESSURE SENSOR 1/2 SIGNAL CIRCUIT SHORTED TO THE (K854) 5-VOLT SUPPLY CIRCUIT
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 5.0 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 7



7. ECM
Reconnect the C2 ECM harness connector.
Ignition on, engine not running.
Leave the Exhaust Pressure Sensor 1/2 harness connector disconnected.
Using a jumper wire, connect the (K182) Exhaust Pressure Sensor 1/2 Signal circuit to the (K400) APPS Return circuit in the sensor harness connector.
With the scan tool, read DTCs.
Did the DTC for (P2455) high voltage go inactive and the DTC for (P2454) low voltage become active?

Yes


- Refer to the INTERMITTENT CONDITION - DIESEL Diagnostic Procedure. Intermittent Condition


No


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