Symptoms
and severity
This code should be considered urgent, as it indicates conditions that could lead to internal damage to the engine or fuel system. The symptoms of a P245F code may include:
- Decreased engine performance
- Excessive black smoke from the exhaust
- Increased engine temperatures
- Transmission temperatures higher than normal
Causes
Potential causes for this code being set are as follows:
- Clogged DPF pressure sensor tubes/pipes
- Faulty DPF pressure sensor
- The diesel exhaust fluid tank may be empty
- Poor quality diesel exhaust fluid
- Open or shorted circuit(s) in the DPF pressure sensor B circuit
- Ineffective DPF regeneration
- The active DPF regeneration system is inoperative
Diagnostic and Repair Procedures
A good starting point is always to check the technical service bulletins (TSBs) for your specific vehicle. Your issue may be a known problem with a published fix from the manufacturer and can save you time and money during diagnosis.
A manufacturer’s service manual, a diagnostic scanner, and a digital volt/ohmmeter will be essential for diagnosing a P245F code. An infrared thermometer may also be helpful.
I would begin my diagnosis with a visual inspection of the related wiring harnesses and connectors; pay close attention to wiring routed near hot exhaust components and/or sharp edges. Test the alternator output, check the battery and battery terminal ends at this time.
I would continue by connecting the scanner and retrieving all stored codes and freeze frame data. Be sure to note this information for future reference. Clear the codes and test-drive the vehicle.
Check that the diesel exhaust fluid is present (if applicable) and is the correct type, especially if the code resets immediately. A lack of diesel exhaust fluid is likely the most common cause for this code being stored. The DPF will not regenerate effectively without the proper type of diesel exhaust fluid. Poor DPF regeneration will lead to increased exhaust pressure.
Using the DVOM, test the DPF pressure sensor. Consult the manufacturer’s service manual for instructions. The sensor should be replaced if it does not meet the manufacturer’s resistance specifications.
Check for obstructions and/or breaks in the DPF pressure sensor supply pipes, if the sensor checks out. Clean or replace the pipes as needed (high-temperature silicone hoses should be used).
If the supply lines are intact and the sensor is operational, begin testing the system circuits. Disconnect all associated controllers before testing resistance and/or continuity with the DVOM. Repair or replace any open or shorted circuits as necessary.
Additional Diagnostic Notes:
- Clogged sensor ports and clogged sensor tubes are common
- Consult the owner’s/service manual to determine if your vehicle is equipped with an active DPF regeneration system or a passive system
- If the DPF pressure sensor hoses are melted or cracked, they may need to be rerouted after replacement