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P2453



DTC P2453

Diagnostic Instructions

* Perform the Diagnostic System Check - Vehicle prior to using this diagnostic procedure. Initial Inspection and Diagnostic Overview
* Review Strategy Based Diagnosis for an overview of the diagnostic approach.
* Diagnostic Procedure Instructions provides an overview of each diagnostic category.

DTC Descriptor

DTC P2453
- Particulate Matter Trap Differential Pressure Sensor Signal Performance

Diagnostic Fault Information






Typical Scan Tool Data






Circuit/System Description

The exhaust differential pressure sensor measures the pressure difference across the inlet and outlet of the diesel particulate filter (DPF). The pressure difference across the DPF increases as the captured particulates in the DPF increase. A diaphragm within the differential pressure sensor is displaced by the pressure changes that occur from particulate matter loading. The sensor translates this action into electrical resistance. The engine control module (ECM) supplies a 5-volt reference circuit and a ground on the low reference circuit. The differential pressure sensor provides a signal voltage to the ECM, relative to the back pressure as a function of exhaust flow, DPF temperature, and soot loading. The ECM converts the signal voltage input into a pressure value.

Conditions for Running the DTC

* The engine has been running and then turned off for at least 60 seconds.
OR
* The engine is running with the pedal position varying rapidly between 0-100 percent.
* DTC P2453 runs continuously when the engine is running.
AND
* DTC P2453 runs once after the ignition has been turned OFF.

Conditions for Setting the DTC

* With the engine OFF the ECM detects that the differential pressure is greater than or less than the calibrated threshold for 0.5 second.
* With the engine running the ECM detects that the differential pressure is greater than or less than the calibrated threshold for 1 second.

Action Taken When the DTC Sets

* DTC P2453 is a Type A DTC.
* A message center or an indicator may display Clean Exhaust Filter.

Conditions for Clearing the MIL/DTC

DTC P2453 is a Type A DTC.

Diagnostic Aids

* A skewed or stuck exhaust differential pressure sensor will cause this DTC to set.
* The flexible part of the exhaust differential pressure lines are made of a high temperature hose that is protected by a braided covering. If the hoses are twisted or bent, they will not return to their normal size and shape. If the hoses are restricted, it may cause this DTC to set.
* A turbocharger charge air cooler (CAC) hoses leak may cause this DTC to set.
* An air induction air leak or a skewed mass air flow (MAF) sensor may cause this DTC to set.
* An engine stall, low engine idle speed, or an engine misfire may cause this DTC to set.

Special Tools

* J 23738-A Mityvac
* J 35555 Metal Mityvac

Circuit/System Verification

1. Verify that DTCs P0101, P0102, P0103, P0234, P0299, P0300-P0308, P0401, P0402, P0652, P0653, P0698, P0699, or P2563 are not set.

^ If any of the DTCs are set, refer to Diagnostic Trouble Code (DTC) List - Vehicle. Diagnostic Trouble Code Descriptions

2. Ignition ON, engine OFF, observe the scan tool Particulate Filter. Pressure Variance parameter. The value should be between -1.0 and +0.3 kPa.
3. Engine running at a warm stabilized idle, observe the scan tool Particulate Filter. Pressure Variance parameter. The value should be between 0.0-3.0 kPa.
4. Engine running at a warm stabilized idle, observe the scan tool Particulate Filt. Pressure Variance parameter. Increase the engine speed to 3,000 RPM. The value should increase.
5. Operate the vehicle within the Conditions for Running the DTC to verify that the DTC does not reset. You may also operate the vehicle within the conditions that you observed from the Freeze Frame/Failure Records data.

Circuit/System Testing

Important: Perform the Repair Verification after completing the Circuit/System Testing.

1. Verify the integrity of the DPF system by visually and physically inspecting any of the following conditions:

* Any damaged exhaust system components
* Loose or improperly installed exhaust system components-Ensure the smaller diameter pressure line is connected to the front of the DPF and to the smaller port of the differential pressure sensor.
* Restrictions in the exhaust differential pressure sensor ports
* Damaged, bent, restricted, or kinked exhaust differential pressure lines-The lines should not be modified and should have a continuous downward gradient from the sensor.
* Inspect for fuel contaminates.

2. Verify the integrity of the entire air induction system by inspecting for the following conditions:

* A loose air inlet duct
* A loose turbocharger air inlet clamp
* A damaged air cleaner housing
* A missing or damaged air cleaner restriction indicator
* A loose, leaking, or cracked intake manifold air resonator

3. Remove and inspect the flexible part of the exhaust differential pressure lines for internal restrictions.

^ If a condition is found replace the exhaust pressure lines.

4. Engine running, verify that the scan tool Particulate Filt. Pressure Variance parameter is greater than 0 kPa (0 psi), and increases as engine speed is increased.

^ If less than the specified range, and the parameter decreases as engine speed is increased, inspect for incorrect differential pressure line routing.

5. Ignition OFF, disconnect the harness connector at the exhaust differential pressure sensor.
6. Ignition OFF for 90 seconds, test for less than 5 ohms between the low reference circuit terminal 1 and ground.

^ If greater than the specified range, test the low reference circuit for an open/high resistance. If the circuit tests normal, replace the ECM.

7. Ignition ON, test for 4.8-5.2 volts between the 5-volt reference circuit terminal 3 and ground.

^ If less than the specified range, test the 5-volt reference circuit for a short to ground or an open/high resistance. If the circuit tests normal, replace the ECM.
^ If greater than the specified range, test the 5-volt reference circuit for a short to voltage. If the circuit tests normal, replace the ECM.

8. Verify the scan tool Particulate Filt. Pressure Variance parameter is greater than 98 kPa.

^ If less than the specified range, test the signal circuit for a short to ground. If the circuit tests normal, replace the ECM.

9. Install a jumper wire between the low reference circuit terminal 1 and signal circuit terminal 2. Verify the scan tool Particulate Filt. Pressure Variance parameter is less than -13.0 kPa.

^ If greater than the specified range, test the signal circuit for a short to voltage or an open/high resistance. If the circuit tests normal, replace the ECM.

10. Ignition OFF for 90 seconds, disconnect the X1 harness connector at the ECM.
11. Test for less than 5 ohms on each of the exhaust differential pressure sensor (DPS) circuits between the following terminals:

* ECM X1 5-volt reference circuit terminal 14 to DPS terminal 3
* ECM X1 signal circuit terminal 43 to DPS terminal 2

^ If greater than the specified range, repair the open/high resistance in the affected circuit.

12. Allow the engine coolant temperature to reach a minimum of 50°C (122°F). With the engine running in Park, depress the accelerator pedal until maximum engine speed is obtained. While the engine is at maximum speed, observe the scan tool Particulate Filt. Pressure Variance parameter. The value should be greater than 5 kPa (0.73 psi).

^ If less than the specified value, inspect the DPF substrate. If the substrate is missing or damaged, replace the DPF.

13. If all circuits, the exhaust system, fuel system, air intake, DPF, and the differential pressure lines test normal, test or replace the exhaust differential pressure sensor.

Component Testing

Important: You must perform the Circuit/System Testing in order to verify the integrity of the exhaust differential pressure sensor circuits before proceeding with Component Testing.

1. Ignition OFF, remove the exhaust differential pressure sensor.
2. Install a 3A fused jumper wire between the 5-volt reference circuit terminal 3 and the corresponding terminal of the exhaust differential pressure sensor. Install a jumper wire between the low reference circuit terminal 1 of the exhaust differential pressure sensor and ground.
3. Connect a DMM between terminal 2 of the exhaust differential pressure sensor and ground.
4. Ignition ON, with the J 23738-A or J 35555 connected to the exhaust differential pressure sensor rear pressure port, slowly apply vacuum while monitoring the voltage on the DMM. The voltage should vary and transition smoothly without any spikes or dropouts.

^ If the voltage is erratic, replace the exhaust differential pressure sensor.

Repair Instructions

* Exhaust Particulate Filter Cleaning (LMM DPF Regeneration Enable) Exhaust Particulate Filter Cleaning (LMM DPF Service Regeneration) for DPF Regeneration Enable
* Exhaust Pressure Differential Sensor Pipe Replacement (Pickup) Exhaust Pressure Differential Sensor Pipe Replacement (Cab/Chassis)
* Exhaust Pressure Differential Sensor Replacement (Pickup) Exhaust Pressure Differential Sensor Replacement (Cab/Chassis)

Repair Verification

Notice: Refer to Diesel Particulate Filter (DPF) Regeneration Enable Notice.

Certain engine control conditions can cause the DPF to overload with soot. It will be necessary to clean the DPF as instructed to remove the excess soot accumulation. To avoid the customer's return to the service department, perform the appropriate Exhaust Particulate Cleaning procedure that is specified in the provided link.
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