For 1990-2009 cars

### Diagnostic Instructions

• | Perform the Diagnostic System Check - Vehicle prior to using this diagnostic procedure.

• | 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 00: Diesel Particulate Filter (DPF) Differential Pressure Sensor Performance

### Diagnostic Fault Information

Circuit | Short to Ground | Open/High Resistance | Short to Voltage | Signal Performance
--- | --- | --- | --- | ---
5-Volt Reference | P0641 00 | -- | P0641 00 | --
Signal | P2454 00 | P2454 00 | P2455 00 | P2453 00
Low Reference | -- | P2455 00 | P2454 00 | --

### Circuit/System Description

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

### Conditions for Running the DTC

• | The engine has been running and then turned off for at least 60 s.

• | 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 s.

• | With the engine running the ECM detects that the differential pressure is greater than or less than the calibrated threshold for 1 s.

### Action Taken When the DTC Sets

DTCs P2453 is a Type A DTC.

### Conditions for Clearing the DTC

DTCs 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.

### Reference Information

#### Schematic Reference

Engine Controls Schematics

#### Connector End View Reference

Component Connector End ViewsComponent Connector End Views

#### Description and Operation

Exhaust Particulate Filter System Description

#### Electrical Information Reference

• | Circuit Testing

• | Connector Repairs

• | Testing for Intermittent Conditions and Poor Connections

• | Wiring Repairs

#### DTC Type Reference

Powertrain Diagnostic Trouble Code (DTC) Type Definitions

#### Scan Tool Reference

Control Module References for scan tool information

#### Special Tools

EN-23738-A Mityvac

For equivalent regional tools, refer to Special Tools.

### Circuit/System Verification

1. Verify that DTCs P0651, P2454 and P2455 are not set.

⇒ | If any of the DTCs are set, refer to Control Module References.

2. Ignition ON, engine OFF, observe the scan tool DPF Differential Pressure parameter. The value should be between -1.0 kPa to +0.5 kPa (-0.14 PSI to 0.07 PSI).
3. Engine running at a warm stabilized idle, observe the scan tool DPF Differential Pressure parameter. The reading should be between 0.0-3.0 kPa (0.0-0.43 PSI)
4. Engine running at a warm stabilized idle, observe the scan tool DPF Differential Pressure parameter. Increase the engine speed to 3 000 RPM. The value should increase.
5. Operate the vehicle within the Conditions for Running the DTC. You may also operate the vehicle within the conditions that you observed from the Freeze Frame/Failure Records data.

### Circuit/System Testing

Note: 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 changed and should have a continuous downward gradient from the sensor.

2. 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.

3. Engine running, verify that the scan tool DPF Differential Pressure 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.

4. Ignition OFF, disconnect the harness connector at the B154 Diesel Particulate Filter Pressure Sensor.
5. Ignition OFF and scan tool disconnected for 90 s, test for less than 5 Ω between the low reference circuit terminal 2 (X1) 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 K20 Engine Control Module (ECM).

6. Ignition ON, test for 4.8-5.2 V between the 5-volt reference circuit terminal 1 (X1) 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 K20 Engine Control Module (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 K20 Engine Control Module (ECM).

7. Verify the scan tool DPF Differential Pressure parameter is between 4.8-5.2 V.

⇒ | If less than the specified range, test the signal circuit for a short to ground. If the circuit tests normal, replace the K20 Engine Control Module (ECM).

8. Install a jumper wire between the low reference circuit terminal 2 (X1) and signal circuit terminal 3 (X1). Verify the scan tool DPF Differential Pressure parameter is less than 0.5 V.

⇒ | 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 K20 Engine Control Module (ECM).

9. Ignition OFF for 90 s, disconnect the X1 harness connector at the K20 Engine Control Module (ECM).
10. Test for less than 5 Ω between the 5-volt reference circuit B154 Diesel Particulate Filter Pressure Sensor terminal 1 (X1) and the K20 Engine Control Module (ECM) 5-volt reference circuit terminal 27 (X2)

⇒ | If greater than the specified range, test the 5-volt reference circuit for an open/high resistance. If the circuit tests normal, replace the K20 Engine Control Module (ECM).

11. Test for less than 5 Ω between the signal circuit B154 Diesel Particulate Filter Pressure Sensor terminal 3 (X1) and the K20 Engine Control Module (ECM) signal circuit terminal 59 (X2).

⇒ | If greater than the specified range, test the signal circuit for an open/high resistance. If the circuit tests normal, replace the K20 Engine Control Module (ECM).

12. If all circuits DPF, and the differential pressure lines test normal, test or replace the B154 Diesel Particulate Filter Pressure Sensor.

### Component Testing

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

#### Static Test

1. Ignition OFF, remove the B154 Diesel Particulate Filter Pressure Sensor.
2. Install a 3 A fused jumper wire between the 5-volt reference circuit terminal 1 and the corresponding terminal of the B154 Diesel Particulate Filter Pressure Sensor. Install a jumper wire between the low reference circuit terminal 2 of the B154 Diesel Particulate Filter Pressure Sensor and ground.
3. Connect a DMM between the signal circuit terminal 3 and ground.
4. Ignition ON, with the EN-23738-A Mityvac , slowly apply vacuum to the sensor while observing the voltage on the DMM. The voltage should vary and transition smoothly without any spikes or dropouts.

⇒ | If the voltage is erratic, replace the B154 Diesel Particulate Filter Pressure Sensor.

### Repair Instructions

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

• | Exhaust Pressure Sensor Replacement

• | Control Module References for ECM replacement, setup, and programming