EGR Position Sensor – EVP Sensor

The EGR valve position sensor – EVP Sensor (EGR valve position sensor) is an automotive electronic part that bases its operation on the positioning of the EGR valve, evacuation, and recirculation of exhaust gases. This technology was born as a control measure against the harmful and polluting gases generated by the combustion of vehicles.

Therefore, you must consider its operation since it also affects the behavior and performance of the engine.

What is the EVP Position Sensor?

This part is a control or monitoring point for the EGR valve or for regulating the exhaust gases. Virtually, the EVP Sensor is found in all vehicles, but especially those with diesel injection. And it is considered a piece of the anti-pollution system, so it is one of the points to be evaluated in the reviews.

This sensor itself turns out to be a linear action potentiometer where you will find three pins, ground, positive, and signal.

How to identify the EVP Sensor in your vehicle?

Everything will depend on the vehicle you have. Some manufacturers specify in the vehicle manual a schematic or diagram of the location of each sensor that could help you.

About this sensor, there are no significant variations. So, look at your engine, and between the intake and the exhaust, you are sure to notice the EGR valve. This turns out to be a communication channel between them. And coupled to this valve will be the EVP Sensor.

EVP Position Sensor Function

The EGR Valve Position Sensor – EVP Sensor monitors the valve position where the exhaust gas recirculates. This function is fulfilled by capturing the position of the EGR valve after the vehicle’s ECU has sent the signal.

How does the EVP Sensor work?

It is a process or continuous cycle where the EVP Sensor verifies the position of the EGR valve and sends signals to the ECU so that it determines the operation based on the temperature, speed, and load of the gases and the engine. The process occurs several times per second.

The changes that occur in the opening of the EGR valve generate an electrical resistance that the EVP Sensor registers. This voltage signal will increase as the valve opens. Which indicates that it will have more excellent resistance as it closes.

The sensor is positioned on the valve in the mechanical aspect, and the sensor has a shaft. The valve is pressing this shaft as it opens. In this way, the gas recirculation flow is controlled by the ECU.

EVP Sensor interference in EGR valve

Today, the emission control of vehicles is measured and reviewed annually. So these two components, the EVP Sensor and the EGR valve, work in sync. This function between the two allows the combustion gases to pass back into the system and burn at a higher temperature. They are allowing harmful gases to be less than the environment. At the same time, it will enable the same gases to recirculate to serve as additional engine performance.

EVP Sensor Faults

It is a sensor that tends to suffer wear since its operation is very constant. And the failures of this affect the operation of the EGR valve. What in turn, you will perceive an increase in exhaust emissions. And it can even cause engine failure.

EGR valve or sensor failure symptoms

In addition, there may be other symptoms associated with this failure:

  • Intense black smoke from the exhaust.
  • Pull us when starting.
  • Catalytic converter overheating.
  • Unstable idle.

OBD2 Codes Related to EVP Sensor

When the sensor or the valve is faulty, the check engine light will come on in the cluster. And when scanning it, the code will usually be P0405. Which has the following meaning “low voltage either output or input.”

Other related errors in OBD2 protocol

P0401: Insufficient gas recirculation.

31-32: EGR valve control fault.

How to test the EVP Sensor?

To verify the status of the sensor, you must have a multimeter. And do the following:

  • Identify each sensor terminal. Remember, a ground, a positive or voltage and an output signal pin.
  • Select the volts option on the multimeter.
  • Place the tip of the multimeter lead on the output pin and begin pulsing or depressing the sensor tip. Every time you do this it should give you a reading on the multimeter.

How to maintain the EVP Sensor?

There is little that can be done in maintenance or to clean the EGR Position Sensor. Instead, it is checking conditions. Like, for example, that:

  • The cables are not corroded.
  • The connector is not fractured or sulphated. If the latter is the case, it could be cleaned.
  • The hoses connecting the intake to the exhaust are clean.

Finally, remember that sensors are electronic elements, and they will work well or not. And, although this sensor may not be as named as the others, it considers that its good operation contributes to a healthier environment and fuel savings.

EGR Position Sensor – EVP Sensor

Hi, this is Viney Bhatia, a blogger, an engineer, and your virtual mechanic. You'll get all the latest information about cars, reviews, tips, service methods, and various other things related to automobiles on our blog.

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