Fault code P2143 – exhaust gas recirculation vent control circuit open

Fault code P2143 is called “Exhaust Gas Recirculation Vent Control Circuit Open” 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 P2143

This Diagnostic Trouble Code (DTC) is a general powertrain code. Error P2143 is considered a general code because it applies to all makes and models of vehicles. Although the specific repair steps may vary slightly depending on the model.

Fault code P2143 – exhaust gas recirculation vent control circuit open

Exhaust Gas Recirculation (EGR) systems are continuously monitored and regulated by the Engine Control Module (ECM). Exhaust gas recirculation systems allow your vehicle’s engine to reuse fuel-air mixtures. Which have gone through the combustion process, but have not yet burned completely and efficiently.

By recirculating this “half-burned” mixture and feeding it back into the engine. Exhaust gas recirculation increases fuel economy. Not to mention improving the vehicle’s overall emissions.

The exhaust gas recirculation valves are controlled electronically by electrical solenoids. Or mechanically, with vacuum-operated solenoids. But there are other ways, depending on your make and model of car.

The venting solenoid of the exhaust recirculation system is mainly used to remove unwanted processed exhaust gases. They usually dump this unprocessed exhaust back into the exhaust system for release into the atmosphere. After passing through catalytic converters, resonators, mufflers, etc.

It is important to note that the catalytic converter will burn most of the unburned fuel to prevent the car’s emissions from increasing dramatically.

The Engine Control Module (ECM) controls and regulates numerous sensors, switches, and other systems. The activation of error P2143 or related codes P2144 and P2145 occurs when there is a problem with the exhaust gas recirculation control.

In the case of code P2143 – it means that there is a general malfunction or a circuit failure in the electrical control circuit of the exhaust gas recirculation system.

Symptoms of vehicle malfunctions

The main signal that an error P2143 has occurred is the Malfunction Indicator Lamp (MIL) is also known as the CheckEngine Light.

It can also be warning signs such as:

  1. Check engine control lamp on the control panel will light up (the code will be recorded in the memory as a malfunction).
  2. Decrease of engine power.
  3. Floating revolutions at idle.
  4. Poor acceleration.
  5. Increased fuel consumption.
  6. Symptoms similar to ignition failure.

Error P2143 is of medium severity. Exhaust Gas Recirculation (EGR) system is not mandatory for engine operation. However, it does reduce emissions and also helps the engine run smoothly in various conditions.

Therefore, EGR operation is important if you want your car to run and function optimally. Also, it’s worth noting that soot passing by these systems can build up and cause future problems. Maintain your EGR system properly to avoid unnecessary consequences in the future.

Factors that can cause this error code

The error code P2143 can mean that one or more of the following problems have occurred:

  • Dirty or clogged exhaust gas recirculation system (exhaust gas recirculation valve).
  • Faulty exhaust gas recirculation system vent control solenoid valve.
  • The exhaust recirculation system vent is clogged.
  • Failure of the exhaust gas recirculation valve position sensor or absolute air pressure sensor in the intake manifold.
  • Damage to the vacuum lines or hoses.
  • Short circuit or breakage of electrical wires related to the exhaust gas recirculation system.
  • Loose, corroded or damaged electrical connectors related to the exhaust gas recirculation system.
  • In rare cases, engine control module (ECM) malfunction.

How to fix or reset OBD-2 code P2143

Some suggested steps for troubleshooting and fix the error code P2143:

  1. Connect an OBD-II scanner to the vehicle’s diagnostic connector and read all stored data and error codes.
  2. Clear the error codes from the computer memory and test-drive the vehicle to see if the P2143 code appears again.
  3. If the error code appears again, visually inspect the electrical wires and connectors related to the exhaust gas recirculation system.
  4. If necessary, repair or replace any shorted, broken, damaged, or corroded components.
  5. If the problem persists, check the exhaust gas recirculation system passages for blockage. Inspect the vacuum lines and check thoroughly for vacuum leaks.
  6. Check the operation of the exhaust gas recirculation valve and the vent control solenoid valve.
  7. Check the operation of the exhaust recirculation valve position sensor and the absolute intake manifold air pressure sensor.
  8. Measure the voltage of the system vent control solenoid valve circuit using a digital multimeter.
  9. Compare value with manufacturer’s data sheet, replace faulty valve if necessary.
  10. If problem persists, check and replace engine control module (ECM) if necessary.

Diagnose and repair of problems

The first step in the troubleshooting process for any malfunction, is to review the Technical Service Bulletins (TSB). For known problems with a particular vehicle.

The advanced diagnostic steps are very vehicle specific. They may require, special equipment and knowledge to accurately perform the steps.

Allow your vehicle’s engine to cool down. In most cases, exhaust gas recirculation systems are very hot. Since they are usually installed directly on the exhaust system. Therefore, if you don’t let the engine cool down, you can get burned.

Inspect all vacuum lines, they don’t tolerate high temperatures well, and it’s not uncommon in a recirculation system. Any vacuum line that is burned or broken should be replaced or repaired.

Lines are inexpensive, so it is best to replace all lines with new ones, especially if you find that one has failed. If one has severe wear and tear, it is likely that the others are not far behind.

Be sure to carefully check the integrity of the wire harnesses involved. They often run along and around the exhaust pipe. So it would be a good idea to tie off any loose wires. If you find a burned wire, solder the connections and make sure they are properly insulated.

Inspect the vent solenoid for cracks and water intrusion. Also, make sure that the connectors are properly electrically connected and that the latches are not damaged or broken.

If available with access, you can remove the exhaust recirculation valve to check its condition. These valves are susceptible to significant soot buildup. Use carburetor cleaner and a toothbrush to remove soot from any soiled areas.

On which vehicles does this problem occur most frequently

Fault code P2143 can occur on different vehicles but there are statistics on which brands this occurs most often. Here is a list of some of them:

  • Chevrolet
  • Citroen
  • Dodge (RAM)
  • Ford
  • Mazda
  • Mercedes-Benz (Sprinter)
  • Peugeot
  • Pontiac

Fault code P2143 can sometimes be found with other errors. The most common are the following: P0011, P0121, P0449, P0455, P1516, P2101, P2145, C0700.


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