Technical Description of OBD-II Trouble Code
Exhaust Gas Recirculation Vent Control Circuit /Open
What is the meaning of this?
This is a generic powertrain diagnostic trouble code (DTC) that is typically applicable to OBD-II vehicles. It may be found in vehicle makes such as Citroen, Peugeot, Sprinter, Pontiac, Mazda, Chevy, GMC, Ford, Dodge, Ram, etc.
While driving our vehicles, the ECM (Engine control module) constantly monitors and adjusts the EGR (Exhaust gas recirculation) systems. These systems allow the engine to reuse air/fuel mixtures that have gone through the combustion process but have not burned completely and efficiently. By recycling this “semi-burnt” mixture and reintroducing it to the engine, the fuel economy is increased and overall vehicle emissions are improved.
Most EGR valves nowadays are controlled electronically through electrical solenoids, vacuum controlled solenoids, or other methods depending on the make and model of the vehicle. The EGR vent solenoid is primarily responsible for discarding unneeded recyclable exhaust. Typically, this un-recycled exhaust is vented back into the exhaust system and released into the atmosphere after passing through the catalytic converters, resonators, mufflers, etc. It is important to note that the catalytic converter burns most of the unburnt fuel to prevent an increase in vehicle emissions. The term “exhaust gas recirculation vent control circuit” may refer to a specific wire that is causing the fault, so it is important to consult the service manual to identify the exact physical circuit involved.
While monitoring and adjusting various sensors, switches, and systems, the ECM (engine control module) activates the P2143 code and/or related codes (P2144 and P2145) to indicate a problem with the exhaust gas recirculation vent control circuit.
P2143 indicates a general fault or a loss of continuity in the EGR exhaust gas recirculation vent control electrical circuit.
How severe is this DTC?
In terms of severity, I would classify this fault as moderately severe, and here’s why. The EGR (exhaust gas recirculation) system is not essential for the engine’s operation. However, it does improve emissions and helps the engine run smoothly under different conditions, so its proper functioning is crucial for optimal vehicle performance. Additionally, if left unaddressed for a long time, the soot that passes through these systems can accumulate and cause future problems. Proper maintenance of the EGR system is necessary to avoid any complications.
What are some symptoms of the code?
Some symptoms associated with the P2143 diagnostic code may include:
What are some common causes of the code?
Causes of the P2143 code may include:
What are some diagnostic and troubleshooting steps for P2143?
The first step in troubleshooting any malfunction is to consult the Technical Service Bulletins (TSB) for known issues with the specific vehicle.
Advanced diagnostic steps are highly specific to the vehicle and may require specialized equipment and knowledge for accurate performance. The following are basic steps, but it is recommended to refer to a vehicle-specific repair guide for detailed instructions.
Basic Step #1
Begin by allowing the vehicle’s engine to cool down. EGR (exhaust gas recirculation) systems are typically hot due to their direct connection to the exhaust system. Failure to let the engine cool adequately may result in burns. EGR valves are often mounted directly on the exhaust, while vent solenoids, which control the EGR’s venting, are usually located in the engine bay, often on the firewall. The vent solenoid operates through vacuum control, so there may be multiple rubber vacuum lines running from it to the EGR system. Given the high temperatures in this area, it is important to thoroughly inspect these lines and replace or repair any burnt or broken ones. It is recommended to replace all lines if one is deteriorated, as others may be close to failure as well.
Basic Step #2
Thoroughly check the integrity of the involved harnesses. Since they run along and around the exhaust, it is advisable to secure any loose wires or harnesses out of the way. If a burnt harness or wire is found, solder the connections and ensure proper insulation. Inspect the vent solenoid for cracks or water intrusion. These sensors are exposed to the elements and are often made of plastic, so potential faults should be considered. Additionally, ensure that connectors establish adequate electrical connections and that the tabs are intact and undamaged.
Basic Step #3
If accessible and convenient, remove the EGR valve to inspect its condition. These valves tend to accumulate a significant amount of soot. Use carburetor cleaner and a toothbrush to remove soot from stubborn areas.
