Diagnostic Instructions
DTC Descriptors
DTC P244A: Diesel Particulate Filter Differential Pressure Too Low
DTC P244B: Diesel Particulate Filter Differential Pressure Too High
DTC P244B 11: Diesel Particulate Filter Differential Pressure Too High Above Maximum Threshold
DTC P2453: Diesel Particulate Filter Differential Pressure Sensor Performance
DTC P2453 08: Diesel Particulate Filter Differential Pressure Sensor Performance Signal Invalid
DTC P2453 11: Diesel Particulate Filter Differential Pressure Sensor Performance Above Maximum Threshold
DTC P2453 12: Diesel Particulate Filter Differential Pressure Sensor Performance Below Minimum Threshold
DTC P2453 18: Diesel Particulate Filter Differential Pressure Sensor Performance Signal Amplitude Less Than Minimum
DTC P2453 55: Diesel Particulate Filter Differential Pressure Sensor Performance Expected Number Of Transitions/Events Not Reached
DTC P2453 58: Diesel Particulate Filter Differential Pressure Sensor Performance Incorrect Reaction After Event
Circuit/System Description
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 pressure pipes, which are connected to the DPF pressure sensor, measure the level of soot deposit in the DPF and protect the engine by triggering regeneration when critical soot level is detected in the filter.
Conditions for Running the DTC
P244B, P244B 11, P2453 08, P2453 11, P2453 12, P2453 55, P2453 58
• | The DTCs run continuously when the above condition is met. |
P244B, P244B 11, P2453 08, P2453 11, P2453 12, P2453 55
• | The ignition is switched from ON to OFF. |
• | The DTCs run after a 2 second delay when the above condition is met. |
P2453 58
• | The intake air temperature (IAT) sensor is less than 0°C (32°F). |
• | The DTC runs continuously when the above condition is met. |
Conditions for Setting the DTC
P2453, P2453 08, P2453 18, P2453 55
The ECM detects an invalid signal from the DPF differential pressure sensor for greater than 0.5 seconds.
P244B, P244B 11
The ECM detects the DPF differential pressure sensor signal is greater than 90 kPa (13 psi) for greater than 1 second.
P244A, P2453 12
The ECM detects the DPF differential pressure sensor signal is less than 4 kPa (0.6 psi) for greater than 1 second.
P2453 58
The ECM detects an invalid signal from the DPF differential pressure sensor when the IAT is less than 0°C (32°F).
Action Taken When the DTC Sets
DTCs P244A, P244B, P2453, P2453 11, and P2453 12 are type A DTCs.
DTCs P2453 08, P2453 18, and P2453 55 are type B DTCs.
DTC P2453 58 is a type C DTC.
Conditions for Clearing the DTC
DTCs P244A, P244B, P2453, P2453 11, and P2453 12 are type A DTCs.
DTCs P2453 08, P2453 18, and P2453 55 are type B DTCs.
DTC P2453 58 is a type C DTC.
Reference Information
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
Circuit/System Verification
- Ignition ON, observe the diagnostic trouble code (DTC) information with a scan tool. Verify that no other DTCs are set.
- Ignition ON, observe the scan tool DPF pressure sensor parameter. The parameter should be within 0.45-0.55 volts.
- Engine idling, observe the scan tool diesel particulate filter data parameter. The reading should be within 0-10 kPa (0-1.5 psi).
- 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. DTCs P244A, P244B, P244B 11, P2453, P2453 08, P2453 11,
P2453 12, P2453 55, or P2453 58 should not set.
Circuit/System Testing
- Ignition OFF, inspect for the following:
• | Intake system/charge air hoses for leaks/restrictions |
• | Exhaust system/turbo charger for leaks/restrictions |
• | Air filter for restrictions |
⇒ | If a condition is found, repair as necessary. |
Important: If DTC P2453 58 is set, inspect for moisture in the hoses/pipes to the DPF pressure sensor.
- Ignition OFF, inspect the hose/pipes to the DPF pressure sensor for leaks, or restrictions.
⇒ | If a condition is found, repair as necessary. |
- Ignition OFF, and the MAIN fuse removed, disconnect the harness connector at the DPF sensor.
- Test for less than 5 ohms between the low reference circuit terminal 2 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. |
- Install the MAIN fuse. 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 5-volt reference circuit for a short to ground or 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. |
- Verify the scan tool DPF sensor voltage parameter is greater than 4.8 volts.
⇒ | If less than the specified range, test the signal circuit for a short to ground. If the circuit tests normal, replace the ECM. |
- Install a 1A fused jumper wire between the signal circuit terminal 3 and ground. Verify the scan tool DPF sensor voltage parameter is less than 0.5 volts.
⇒ | 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. |
- Ignition OFF, connect the harness connector at the DPF pressure sensor.
- Ignition ON, verify the scan tool DPF pressure sensor parameter is between 0.45-0.55 volts.
⇒ | If not within the specified range, replace the DPF sensor. |
- If all circuits test normal, replace the DPF.
Repair Instructions
Perform the
Diagnostic Repair Verification
after completing the diagnostic procedure.