Symptoms and Severity
Conditions that could lead to this code may also cause internal damage to the engine or fuel system and should be considered urgent. Symptoms of a P2455 code may include:
- Excessive black smoke from the exhaust
- Increased engine temperatures
- Transmission temperatures higher than normal
- Decreased engine performance
Potential causes for setting this code are:
- Exhaust leaks
- Clogged DPF pressure sensor tubes/pipes
- Open or shorted circuit(s) in the DPF pressure sensor A circuit
- Faulty DPF pressure sensor
- Diesel exhaust fluid tank may be empty
- Poor quality diesel exhaust fluid
- Ineffective DPF regeneration
- Active DPF regeneration system inoperative
Diagnostic and Repair Procedures
A good starting point is always to check the technical service bulletins (TSB) for your specific vehicle. Your issue might be a known problem with a published manufacturer fix that could save you time and money during diagnosis.
To diagnose a P2455 code, you will need a digital volt/ohmmeter, manufacturer service manual, and diagnostic scanner.
I recommend beginning your diagnosis with a visual inspection of related wiring harnesses and connectors. Inspect wiring routed near hot exhaust components and/or sharp edges. Be sure to check alternator output, battery voltage, and battery terminal ends at this time.
Continue by connecting the scanner and retrieving all stored codes and freeze frame data. Remember to note this information for future reference, then clear all stored codes.
Use the DVOM and follow manufacturer recommendations to test the DPF pressure sensor. Consult the service manual for specific instructions. Any sensor that doesn’t meet manufacturer resistance specifications should be replaced.
DPF pressure sensor supply hoses should be checked for obstructions and/or damage if the sensor checks out. Replace burned, cracked, or collapsed hoses (high-temperature silicone hoses are recommended).
If the sensor supply lines are intact and the sensor is operational, you can begin testing system circuits. To avoid damaging the PCM, disconnect all related controllers before testing resistance and/or continuity with the DVOM.
Additional Diagnostic Notes:
- Check DPF regeneration fluid before attempting to diagnose this code
- Clogged sensor ports and blocked sensor tubes are common when this code is stored
- DPF pressure sensor hoses that have melted or been cut may need rerouting after replacement