2014 Jeep Wrangler JK Factory Service Manual 28 - DTC-Based Diagnostics

P2455-DIESEL PARTICULATE FILTER DIFFERENTIAL PRESSURE SENSOR CIRCUIT HIGH

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


Theory of Operation

The Diesel Particulate Filter is an in-line canister filter located in the exhaust system between the engine and the muffler. This filter captures and stores soot particles created by the diesel combustion process. As ash and soot accumulate in the filter, the exhaust pressure at the inlet side of the filter increases as compared to the pressure at the outlet side of the filter. This filter is monitored by the Powertrain Control Module (PCM) with a Differential Pressure Sensor. There is a tube at the inlet and outlet of the Diesel Particulate Filter. A hose is attached to each tube. The other end of the hose is connected to the Differential Pressure Sensor. The Differential Pressure Sensor compares the pressure from each hose and measures the delta pressure (difference between the inlet and outlet) in the Diesel Particulate Filter.



Possible Causes

(K354) EXHAUST DIFFERENTIAL PRESSURE SENSOR 5-VOLT SUPPLY CIRCUIT SHORTED TO VOLTAGE
(K355) EXHAUST DIFFERENTIAL PRESSURE SENSOR SIGNAL CIRCUIT SHORTED TO VOLTAGE
(K951) EXHAUST DIFFERENTIAL PRESSURE SENSOR GROUND CIRCUIT OPEN/HIGH RESISTANCE
EXHAUST DIFFERENTIAL PRESSURE SENSOR
POWERTRAIN CONTROL MODULE (PCM)

Always perform the Pre-Diagnostic Troubleshooting procedure before proceeding. (Refer to 28 - DTC-Based Diagnostics/MODULE, Powertrain Control (PCM) - Standard Procedure).


1. DTC IS ACTIVE



NOTE: If any Sensor Reference DTCs are present, perform the applicable diagnostic procedure before continuing with this test.
1. Ignition on, engine not running.
2. With the scan tool, select View DTCs.


Is the status Active for this DTC?

Yes


No


2. CHECK THE (K355) EXHAUST DIFFERENTIAL PRESSURE SENSOR SIGNAL CIRCUIT FOR A SHORT TO VOLTAGE
1. Turn the ignition off.
2. Disconnect the Exhaust Differential Pressure Sensor harness connector.
3. Turn the ignition on.
4. Measure the voltage of the (K355) Exhaust Differential Pressure Sensor Signal circuit in the Exhaust Differential Pressure Sensor harness connector.


Is the voltage above 5.0 Volts?

Yes


No


3. CHECK THE (K951) EXHAUST DIFFERENTIAL PRESSURE SENSOR GROUND CIRCUIT FOR AN OPEN/HIGH RESISTANCE
1. Disconnect the PCM C1 harness connector.
2. Measure the resistance of the (K951) Exhaust Differential Pressure Sensor Ground circuit between the Exhaust Differential Pressure Sensor harness connector and the PCM C1 harness connector.


Is the resistance below 5.0 Ohms?

Yes


No


4. EXHAUST DIFFERENTIAL PRESSURE SENSOR
1. Turn the ignition off.
2. Reconnect the PCM C1 harness connector.
3. Connect a jumper wire between the (K951) Exhaust Differential Pressure Sensor Ground circuit and the (K355) Exhaust Differential Pressure Sensor Signal circuit in the Exhaust Differential Pressure Sensor harness connector.
4. Turn the ignition on.
5. With the scan tool, view DTCs.


NOTE: The scan tool should display a P2454-Exhaust Differential Pressure Sensor Low DTC with the jumper wire in place.


Does the scan tool display the DTC as described above?

Yes


No


5. POWERTRAIN CONTROL MODULE

1. Using the wiring diagram/schematic as a guide, inspect the wiring and connectors between the Exhaust Differential Pressure Sensor and the Powertrain Control Module (PCM).
2. Look for any chafed, pierced, pinched, or partially broken wires.
3. Look for broken, bent, pushed out or corroded terminals.
4. Perform any Technical Service Bulletins that may apply.


Were any problems found?

Yes


No