Diesel Particulate Filter P200C Overheating Bank 1
OBD2 Error Codes

Diesel Particulate Filter P200C Overheating Bank 1

Diesel Particulate Filter P200C Overheating Bank 1

OBD-II DTC Datasheet

Diesel Particulate Filter Superheat Bank 1

What does this mean?

This Diagnostic Trouble Code (DTC) is a generic transmission code and applies to many OBD-II vehicles (1996 and newer). This may include, but is not limited to, Ford, Hino, Mercedes Benz, VW, etc. Despite the general nature, the exact repair steps may vary depending on the model year, make, model and transmission configuration.

If your OBD-II equipped diesel vehicle has a stored code P200C, it means the powertrain control module (PCM) has detected excessive diesel particulate filter temperature for bank 1 of the engine. Bank XNUMX is the group of engines that contains cylinder number one.

The Diesel Particulate Filter (DPF) in a modern clean-fuel diesel vehicle is designed to reduce harmful exhaust emissions before they enter the atmosphere. Exhaust emissions consist primarily of hydrocarbons (HC), carbon monoxide (CO), nitrogen oxide (NOx) and particulate matter (soot in diesel engines). The DPF is essentially a large filter (with small cells) that can withstand extreme temperatures. The engine exhaust passes through it, and the harmful emissions are trapped by a platinum filter element. The extreme temperatures that occur inside the DPF help burn off the harmful emissions.

The main function of a diesel particulate filter is to reduce the amount of soot from the exhaust gases of a diesel engine. If you have noticed that modern diesel engines run cleaner and with less black smoke than diesels of a few decades ago, this is due to the use of a diesel particulate filter in the exhaust system.

Exhaust Gas Recirculation (EGR) systems take another step in reducing NOx emissions. However, today's larger, more powerful diesel engines cannot meet stringent US federal emission standards with just an EGR, DPF, and NOx trap. For this reason, selective catalytic reduction (SCR) systems have been invented.

SCR systems inject Diesel Exhaust Fluid (DEF) into the exhaust gases upstream of the particulate filter and / or catalytic converter. The precisely timed DEF injection raises the temperature of the filter element and allows it to work more efficiently. This extends the service life of the filter element and helps reduce emissions of harmful exhaust gases into the atmosphere.

Exhaust gas temperature sensors are placed before and after the particulate filter to monitor its temperature and efficiency. The entire SCS system is monitored and controlled by either the PCM or a stand-alone controller (which interacts with the PCM). In any case, the controller monitors the O2, NOx and exhaust gas temperature sensors (as well as other inputs) to determine the appropriate timing for the DEF injection. Precision DEF injection is required to keep the exhaust gas temperature within acceptable parameters and to optimize the filtration of pollutants.

If the PCM detects an excessive DPF temperature (for the first row of engines), a P200C code will be stored and the malfunction indicator light may come on.

Cutout of a typical particulate filter: Diesel Particulate Filter P200C Overheating Bank 1

What is the severity of this DTC?

Any stored DPF codes can be harbingers of a clogged exhaust system. A stored P200C code should be treated as serious and rectified as soon as possible. Catalyst damage can occur if the conditions that contributed to the code persistence are not corrected in a timely manner.

What are some of the symptoms of the code?

Symptoms of a P200C trouble code may include:

  • Reduced engine performance
  • Excessive black smoke from vehicle exhaust
  • Decreased fuel efficiency
  • Other codes related to emissions

What are some of the common causes for the code?

Reasons for this code may include:

  • Broken SCR system
  • Defective SCR injector
  • Incorrect or insufficient DEF fluid
  • Defective exhaust gas temperature sensor
  • Bad SCR controller or programming error
  • Exhaust leaks in front of the catalyst
  • Installation of non-original or high-performance exhaust system components

What are some steps to troubleshoot the P200C?

If the SCR codes are also stored, they should be cleared before attempting to diagnose the stored P200C. Exhaust leaks in front of the catalytic converter must be repaired before attempting to diagnose this type of code.

To diagnose the P200C code, you will need access to a diagnostic scanner, digital volt / ohmmeter (DVOM), infrared thermometer with laser pointer, and vehicle-specific diagnostic information source.

If you can find a Technical Service Bulletin (TSB) corresponding to the year of manufacture, make and model of the vehicle; as well as engine displacement, stored code / codes and symptoms detected, it can provide useful diagnostic information.

You need to start your diagnosis by visually inspecting the SCR injection system, exhaust gas temperature sensors, NOx sensors, and oxygen sensor harnesses and connectors (02). Burnt or damaged wiring and / or connectors must be repaired or replaced before proceeding.

Then connect the scanner to the vehicle diagnostic socket and retrieve all stored codes and corresponding freeze frame data. Make a note of this information before clearing codes and test driving the vehicle until the PCM enters ready mode or the code is reset.

The code is intermittent and can be much harder to diagnose (currently) if the PCM goes into ready mode. In this case, the conditions that contributed to the retention of the code may need to worsen before an accurate diagnosis can be made.

If the code resets, search your vehicle information source for diagnostic block diagrams, connector pinouts, connector face views, and component test procedures and specifications. You will need this information to complete the next step in your diagnosis.

Use an infrared thermometer to determine the actual temperature before and after the DPF. Observe the scanner data flow to compare your actual results with the information on the scanner data display screen. Also compare the data from the exhaust gas temperature sensors between the rows of engines. If exhaust gas temperature discrepancies are found, check the corresponding sensors using the DVOM. Sensors that do not meet manufacturer's specifications should be considered defective.

If all sensors and circuits are working properly, suspect that the diesel particulate filter is defective or that the SCR system has failed.

  • Make sure the DEF reservoir is filled with the correct fluid and the SCR system is working properly.

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Need more help with a P200C code?

If you still need help with DTC P200C, post a question in the comments below this article.

NOTE. This information is provided for informational purposes only. It is not intended to be used as a repair recommendation and we are not responsible for any action you take on any vehicle. All information on this site is protected by copyright.

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