The diesel exhaust after-treatment system consists of an under hood pre-catalytic converter and an underbody catalytic converter. The underbody catalytic converter also consists of the main Diesel Oxidation Catalyst (DOC) and the coated Diesel Particulate Filter (DPF). One of the main purposes of the DPF is to collect particulates from the engine exhaust in order to minimize discharge of soot to the atmosphere. The soot particles accumulate in the channels of the DPF and are burned off at regular intervals through a process called regeneration. This prevents the DPF from clogging. The ECM commands the DPF regeneration after calculating various vehicle conditions such as DPF pressure difference, exhaust gas temperature, engine oil quality, engine speed, etc. Excessive accumulation of the soot in the DPF can cause a drop in the engine performance. During regeneration, additional fuel is injected via multiple post injections in order to increase the exhaust gas temperature. During this period, the DPF temperature is raised to approximately 600°C and the accumulated soot is oxidized or burned off into carbon dioxide (CO2).

The ECM detects that the regeneration demand exists after the maximum regeneration time has passed.

DTC P2458 is a type B DTC.

DTC P2458 is a type B DTC.

Schematic Reference

Engine Controls Schematics

Connector End View Reference

Electrical Information Reference

DTC Type Reference

Powertrain Diagnostic Trouble Code (DTC) Type Definitions

Scan Tool Reference

1. Ignition ON, observe the diagnostic trouble code (DTC) information with a scan tool. Verify that no other DTCs are set.

⇒	If any other DTCs are set, refer to Diagnostic Trouble Code (DTC) List - Vehicle for further diagnosis.

2. Engine idling, observe the scan tool diesel particulate filter data parameter. The parameter should be greater than 2 kPa (0.29 psi).
3. Operate the vehicle within the conditions for running the DTC. You may also operate the vehicle within the conditions that are captured in the Freeze Frame/Failure Records List.

1. Ignition OFF, inspect the hose/pipes to the DPF pressure sensor for leaks, or restrictions.

⇒	If a condition is found, repair as necessary.

2. Disconnect the harness connector at the DPF sensor.
3. Ignition ON, test for less than 0.2 volt between the low reference circuit terminal 2 and ground.

⇒	If greater than the specified range, test the circuit for a short to voltage. If the circuit/connections test normal, replace the ECM.

4. Ignition OFF, test for less than 5 ohms of resistance between the low reference circuit terminal 2 and ground.

⇒	If greater than the specified range, test the circuit for an open/high resistance. If the circuit/connections test normal, replace the ECM.

5. Ignition ON, test for 4.8-5.2 volts between the 5-volt reference circuit terminal 1 and ground.

⇒	If less than the specified range, test the circuit for a short to ground or open/high resistance. If the circuit/connections test normal, replace the ECM.

⇒	If greater than the specified range, test the circuit for a short to voltage. If the circuit/connections test normal, replace the ECM.

6. Verify that the scan tool DPF sensor parameter is less than 7 kPa (1 psi).

⇒	If greater than the specified range, test the signal circuit for a short to voltage. If the circuit/connections test normal, replace the ECM.

7. Install a 3A fused jumper wire between the signal circuit terminal 3 and the ground circuit terminal 2. Verify that the DPF sensor parameter is greater than 10 kPa (1.5 psi).

⇒	If less than the specified range, test the signal circuit for a short to ground or an open/high resistance. If the circuit/connections test normal, replace the ECM.

8. Ignition OFF, connect the harness connector at the DPF pressure sensor.
9. Ignition ON, observe the scan tool DPF pressure sensor parameter. The scan tool should display XX.

⇒	If greater than the specified range, replace the DPF sensor.

10. If all circuits/connections test normal, replace the DPF.

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.