P246C - OBD II Trouble Code

January 31, 2017

Our automotive experts have put together the following information about the P246C diagnostic trouble code. We've provided the common symptoms that occur when this code is set along with the frequent repairs that address the issues related to the P246C code.

OBD II Fault Code

  • OBD II P246C

OBD-II Code Decreased engine performance is defined as a Diesel Particulate Filter Restriction - Forced Limited Power

Diesel Exhaust Fluid (DEF) is used to assist in converting leftover exhaust particles to harmless gases. In order to burn off those particles, the temperature of the exhaust system needs to increase. the injection of DEF Fluid into the exhaust stream brings Diesel Particulate Filter (DPF) up to temperature. The system is then able to convert harmful NOx to Nitrogen, Carbon Dioxide, and water. The Reductant Catalyst (SRC) was added to further reduce any NOx was still in the exhaust stream. The engine computer (PCM) monitors the exhaust pressure before and after the Diesel Particulate Filter (DPF). Excessively high pressures on the inlet side indicate a restriction on the DPF. The PCM will set code P246C. The PCM may also limit power available from the engine to prevent damage to additional components.

Decreased engine performance Symptoms

  • Decreased engine performance

Common Problems That Trigger the P246C Code

  • Diesel Particulate Filter (DPF) failure
  • Manual DPF regeneration must be completed
  • Powertrain Control Module (PCM) failure
  • Powertrain Control Module (PCM) software needs to be updated

About the Author

Brad Kava is an automotive expert at RepairPal, the leading online source of auto repair resources and estimates. With many ASE Master certified mechanics on staff who have decades of experience, RepairPal knows all the fine points of car repair.

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