Fault code P200D – diesel particulate filter over temperature (Bank 2)

Fault code P200D is called “Diesel Particulate Filter Over Temperature (Bank 2)” but in different programs it may be called differently. This fault designation applies to all vehicles equipped with OBD-II.

Technical description and explained code P200D

If your OBD-II equipped diesel engine vehicle has stored code P200D. This means that the control module (PCM) has detected an elevated particulate filter temperature Bank 2.

Fault code P200D – diesel particulate filter over temperature (Bank 2)

The diesel particulate filter, is designed to reduce harmful exhaust emissions before they enter the atmosphere. Exhaust gases consist mainly of hydrocarbons (HC), carbon monoxide (CO), nitrogen oxide (NOx) and particulate soot.

The diesel particulate filter is a coarse (fine mesh) filter capable of withstanding extreme temperatures. Engine exhaust flows through it, and harmful emissions are trapped in the platinum filter element. The extreme temperatures created inside the particulate filter help burn off harmful exhaust elements.

The main purpose of a diesel particulate filter is to reduce the amount of soot in the exhaust of a diesel engine.

Selective Catalytic Reduction (SCR) systems inject Diesel Exhaust Fluid (DEF) into the exhaust before the particulate filter. A precisely timed injection of DEF raises the temperature of the filter element and allows it to operate more efficiently.

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 either by the PCM or by a separate controller that communicates with the PCM.

The controller monitors the O2, NOx, and exhaust gas temperature sensors to determine the appropriate timing for DEF injection. Accurate DEF injection is necessary to keep exhaust temperatures within acceptable limits and optimize pollutant filtration.

If the PCM detects an elevated particulate filter temperature (Bank 2). Then code P200D will be stored in the memory and the malfunction indicator light may illuminate.

Symptoms of vehicle malfunctions

The main signal that an error P200D has occurred is the Malfunction Indicator Lamp (MIL) is also known as the CheckEngine Light.

It can also be warning signs such as:

  1. The “Check engine” control lamp on the control panel will light up (the code will be memorized as a fault).
  2. Other related fault codes may also be present.
  3. Reduced engine power.
  4. Increased fuel consumption.
  5. Black smoke coming out of the exhaust pipe.

Any saved particulate filter codes may be a sign of a clogged exhaust system. A stored P200D code should be considered serious and corrected as soon as possible.

Factors that can cause this error code

The error code P200D can mean that one or more of the following problems have occurred:

  • Faulty SCR system.
  • Wrong or insufficient DEF fluid.
  • Defective exhaust temperature sensor.
  • Air leak in front of DPF changes sensor reading.
  • Faulty SCR controller or programming error.

How to fix or reset OBD-2 code P200D

Some suggested steps for troubleshooting and fix the error code P200D:

  1. Read all stored data and error codes with an OBD-II scan tool.
  2. Clear the error codes from the computer memory.
  3. Test-drive the vehicle to find out if fault P200D appears again.
  4. Visually inspect the SCR system.
  5. Check the particulate filter as well as the exhaust temperature sensor.
  6. Check the DEF fluid as well as the system for air leaks.
  7. If the error persists, check the SCR controller.

Diagnose and repair of problems

It is better to start troubleshooting fault P200D with a visual inspection of relevant harnesses and connectors. Particular attention should be paid to wiring near hot exhaust components and sharp edges.

The exhaust temperature and NOx sensors should then be checked with a multimeter. If the sensors do not meet the manufacturer’s resistance requirements, they must be replaced.

If the sensors are OK, check the hoses for blockages or breaks and clean or replace them if necessary. Use high temperature silicone hoses for replacement.

The hoses to the DPF pressure sensor may be melted or cracked from the temperature. Therefore, it may be necessary to reroute them when replacing them to eliminate the high temperature elements.

After testing the sensors and inspecting the hoses, check the electrical circuitry of the system. Disconnect all associated control modules before checking the resistance with a multimeter. If necessary, repair or replace damaged or shorted circuits.

By following all recommendations, the P200D fault will most likely be corrected and will disappear. If it does not, the problem may be a faulty SCR controller.

On which vehicles does this problem occur most frequently

Fault code P200D can occur on different vehicles but there are statistics on which brands this occurs most often. Here is a list of some of them:

  • Mercedes-Benz

Fault code P200D can sometimes be found with other errors. The most common are the following: P2002, P2003, P200B, P200C, P2016, P2023.


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