Error Code P20A4: What It Means & What To Do?

<<See All OBD Codes

The trouble code P20A4 can be explicated as Reductant Purge Control Valve Stuck Open. This error code would indicate an issue with the circuit which controls the reductant purge control valve. This trouble code is generic, which would mean that it can apply to all the vehicles which are equipped with the OBD-II or the vehicles which are made since 1996 up to the present. The specifications on the definition, the troubleshooting steps as well as repairs can always vary from one vehicle make to another. This can happen because of a lot of reasons and the mechanic should diagnose the specific cause for this code.

It is the engine control module which would examine the reductant purge control valve circuit.This trouble code would be set by the ECM when the reductant purge control valve circuit would not be as per the parameters set by the manufacturer.

What causes this problem with the Reductant Purge Control Valve Stuck Open?

• Faulty control module ground strap
• Malfunctioning connector
• Reductant purge control valve might be flawed
• There can be distorted wiring
• The PCM or ECM might not be functioning properly
• Defective fuse or fuse-able link

1. Engine Control Module - The solenoid might cause a short in the engine control module because of corrosion in the solenoid or the wire running from the solenoid to the ECM harness.
2. Electronic Control Unit – The ECU power management control module keeps in check the hybrid battery charging functions. If the ECU is faulty, the battery pack will not be able to properly get charged and thus, the ECU might need replacement.
3. Powertrain Control Module - A trouble with the PCM would mean that it is unable to determine the right fuel mixture and would send the car engine either more or less fuel than it requires. Now when the engine gets more, the carbon emission would increase and fuel economy would drop. In case of the opposite, the engine will choke, stutter, and might start stalling sometimes.
4. Fuel Injector – Bad fuel injectors can cause starting issues, poor idles and affected performance. Thus, the replacements are in order. Buy new fuel injectors now!
5. Exhaust Gas Recirculation Valve - If the PCM detects any fault in the vehicle’s EGR valve circuit, it will set up the check engine light so that the driver is notified about the fault. Properly check for the EGR valve faults leading to this OBD code getting stored in the system. Get the faulty EGR valve replaced or else this fault code can turn up.
6. Diesel Exhaust Fluid Pump – Faulty DEF pump can lead to increased emission and affected vehicle performance. It can also hamper the fuel economy and the power output of the vehicle. Thus, replace faulty DEF pump now!
7. Diagnostic Tool – Usually any OBD code problem requires deep insight into the problem and high grade tools in order to fix it properly. Thus, buy quality diagnostic tools form us!

It is essential to know the symptoms of an issue as only then you would be able to solve the problem. So that’s why we have listed out some major symptoms of OBD Code P20A4 here:

Common Symptoms

• Illumination in the service engine soon light
• Decline in the fuel economy
• Bad engine performance

If you wish to correct this fault code, then you have to follow certain steps. Correcting a problem needs your careful attention. Here are some ways with the help of which you will be able to correct the OBD Code P20A4:

• Carefully adjust the faults in the reductant purge control valve
• Adjust the flawed PCM or programming error
• You must fix the defective ground straps
• It is essential to restore the flawed wiring
• Rehabilitate the defaults in the fuse or fuse-able link
• It is necessary to perform proper service of the unsound ECM

Parts Avatar Canada is here to solve all your issues related to car parts. We have stocked a wide range of best priced pcm, ecm, reductant purge control valve, diesel exhaust fluid, reductant tank heater, DEF system, reductant pump, reductant purge control valve, pressure sensor, temperature sensor, filters, reductant injector, fuse able link and a lot more to help you out in fixing your car.

If you want to easily diagnose this trouble code, then you must follow the steps which are mentioned here as below:

The advanced steps become very vehicle specific and require the appropriate advanced equipment to perform accurately. These procedures require a digital multimeter and the specific technical references for the vehicle. Voltage requirements will vary based of the specific year, make and model of the vehicle. Then after that the next step is to find all the constituents which are related to the reductant purge control valve circuit and then search for obvious physical damage. As per the particular vehicle, the DEF system might incorporate several constituents which include a reductant pump, purge valve, pressure sensor, integrated level sensor, temperature sensor, system heaters, filters, an electrically controlled reductant injector and a reservoir.

A thorough visual inspection should be performed to inspect the related wiring for obvious defects such as scraping, rubbing, bare wires, or burn spots. Then after that it is important to examine the connectors and connections for security, corrosion and damaged pins. The process should include all wiring connectors and connections to all components including the PCM or ECM.

Consult the particular tech data for the automobile to check if a fuse or fuse-able link is incorporated into the circuit. The advanced steps become very automobile specific and need the appropriate advanced equipment to perform correctly. These procedures require a digital multimeter and the specific technical references for the vehicle. Now in this case, a pressure gauge may also be needed to assist the process of troubleshooting. The reference voltage and the acceptable ranges might differ depending upon on the particular vehicle and the circuit configuration. Particular technical data will include troubleshooting charts and the appropriate sequence to follow assisting you with correct diagnosis.

Now if an absence of a power source or ground is identified in this process, then there would be a need of continuity testing to inspect integrity of the wiring, connectors and other constituents. Make sure to perform continuity tests with the power removed from the circuit and the normal readings for wiring and connections should be 0 ohms of resistance. Resistance or no continuity would indicate that there are some faults in the wiring, so it should be repaired or restored. Then a continuity test should be performed from the PCM or ECM to the frame will confirm the serviceability level of ground straps and ground wires. The presence of resistance would indicate that the connection is loose or there is corrosion.

Common Mistakes When Diagnosing The P20A4 Code

• Reductant purge valve might start failing
• Some issues related to the powertrain control module
• Issues with the car wiring