How to replace the EVP shutdown solenoid
An EGR valve is required for the EGR system in your vehicle. For this valve to work, the EVP shutdown solenoid must control its position and operation.
The automotive industry has experienced periods of conflict, especially when trying to integrate modern technology into old components. For example, in the early to mid-1990s, many car manufacturers began to move from mechanically controlled systems to fully computer and electronically controlled systems. An example of this was that older vacuum driven EGR systems were gradually adapted until they were eventually fully computer controlled. This created a hybrid design type for the EGR system and parts were created to speed up this conversion. One of these parts is known as the EVP shutdown solenoid or EGR valve position solenoid and was used in cars, trucks and SUVs sold in the US from 1991 until the early 2000s.
Introduced in 1966 as an attempt to reduce vehicle emissions, the EGR system is designed to redistribute exhaust gases containing unburned fuel (or vehicle emissions) back into the intake manifold, where they are combusted in the combustion process. By giving unburned fuel molecules a second chance to burn, vehicle emissions leaving the exhaust system are reduced and fuel economy is generally improved.
Early EGR systems used a vacuum control system. Modern cars, trucks, and SUVs use computer-controlled EGR valves that contain multiple sensors and controls that often monitor the position and operation of the EGR system for optimum performance. In between these two developments, different components have been developed to perform the same task of measuring and monitoring the operation of the EGR system. In this second generation system, the EVP shutdown solenoid or EGR valve position solenoid is connected to the EGR valve via a vacuum line and is usually mounted separately from the EGR valve. In contrast, today's more modern EVP position sensors are mounted on top of the EGR valve and connected to the electrical wiring that controls and controls its operation.
The job of the EVP shutdown solenoid is to control the flow of the EGR valve. The data is monitored by a sensor built into the EVP shutdown solenoid, which is communicated to the vehicle's engine control module (ECM) and supported by a vacuum hose attached to a vacuum pump. If the shutdown solenoid becomes dirty (usually due to excess carbon buildup from unburned fuel in the exhaust system), the sensor may fail or jam. If this happens, it can lead to more vehicle emissions entering the combustion chamber, eventually creating a rich air-fuel ratio.
When the fuel cannot burn efficiently, excess fuel comes out of the car's exhaust, which usually causes the car to fail its emissions test and can damage the engine and other mechanical components under the hood.
Unlike the EVP position sensor, the EVP trip solenoid is mechanical in nature. In many cases, the solenoid spring becomes stuck and can be cleaned and repaired without replacing the device. However, this process is incredibly complex and should only be done by a certified technician, such as at AvtoTachki.
There are a number of warning signs or symptoms of a failed EVP shutdown solenoid that can alert the driver to a problem with this component. Some of them include the following:
The Check Engine light comes on. The first sign of a mechanical problem with the EVP shutdown solenoid is the Check Engine light coming on. Because this part is controlled by the vehicle's onboard computer, a faulty solenoid will cause an OBD-II error code to illuminate the Check Engine light on the dashboard. The code most commonly associated with an EVP solenoid disconnect issue is P-0405. Although it can be repaired, it is recommended to replace this part or the entire EGR/EVP valve body and reset the error codes with a diagnostic scanner to check.
The vehicle failed the emissions test. In some cases, failure of this part causes the EGR valve to feed more unburned fuel into the combustion chamber. This will result in a rich air-fuel ratio and may cause the emissions test to fail.
The engine is difficult to start. A broken or damaged EVP shutdown solenoid will usually affect start performance, including idling, which can also result in rough idle, misfiring, or low engine speeds.
Due to their remote location, most EVP shutdown solenoids are very easy to replace. This process is further simplified by the fact that most cars made in the 1990s and early 2000s did not have multiple engine covers or complex air filtration and intake manifold designs that would interfere with the solenoid's location.
- AttentionNote: Although the location of the EVP shutdown solenoid is usually very easily accessible, each manufacturer has their own unique instructions for removing and replacing this part. The steps below are general instructions for replacing the EVP shutdown solenoid on most domestic and imported vehicles made between the 1990s and early 2000s. It is always a good idea to purchase a service manual for the exact make, model and year of your vehicle so you can follow the manufacturer's recommendations.
Part 1 of 2: Replacing the EVP Shutdown Solenoid
Before you decide to replace the EVP shutdown solenoid, you need to know exactly what type of installation you have. Some of the older EGR systems have a separate EVP shutdown solenoid or EGR valve position solenoid that is connected to the EGR valve by a vacuum hose. It is also usually connected to a back pressure sensor.
Due to differences in customization options, it is highly recommended that you purchase and read the service manual for your specific vehicle make, model, and year before purchasing new parts or attempting to replace them. In many cases, you may also need replacement gaskets, so check your service manual again to find out exactly what parts you will need for your vehicle.
Most ASE certified mechanics recommend replacing the EGR valve and EVP shutdown solenoid at the same time, especially if you're going to be running the car for more than a year. Usually, when one part fails, another is next to it. Keep in mind that the following are general instructions for replacing the solenoid and EGR valve.
Necessary materials
- Flashlight or droplight
- Clean shop rag
- Carburetor cleaner
- Set of socket or ratchet wrenches; ¼" actuator if the EGR valve is located near the generator
- OBD-II Diagnostic Code Scanner
- Replacing the EGR valve if you are replacing this part at the same time
- Replacing the EVP shutdown solenoid and any necessary hardware (such as gaskets or additional vacuum hoses)
- Service manual specific to your vehicle
- silicone
- Flat and Phillips screwdrivers
Protective equipment (safety goggles, protective gloves, etc.)
AttentionA: According to most maintenance manuals, this job will take one to two hours, so make sure you have enough time to complete the repair. Most of this time is spent removing engine covers, air filters, and some electronic harnesses. You will also be replacing the EVP shutoff solenoid away from the vehicle, so make sure you have a clean work area to disassemble the EGR valve and prepare for installation.
Step 1: Disconnect the car battery. Locate the vehicle battery and disconnect the positive and negative battery cables.
Keep the battery cables away from the terminals to avoid accidental sparking or sticking.
Step 2: Remove any covers or components blocking the EGR valve.. Consult your vehicle's service manual for specific instructions on how to remove any components blocking access to the EGR valve.
It could be engine covers, air cleaners, or any other accessory that will prevent you from accessing this valve.
Step 3: Locate the EGR valve. On most domestic vehicles manufactured from 1996 to the present, the EGR valve will be located at the front of the engine above the generator.
This arrangement is especially common in minivans, trucks, and SUVs. Other vehicles may have an EGR valve located near the rear of the engine.
Attached to the valve are two hoses (usually metal), one coming from the vehicle's exhaust pipe and the other going to the throttle body.
Step 4: Remove the vacuum hose attached to the EGR valve.. If a vacuum hose is attached to the EGR valve, remove it.
Check the condition of the hose. If it is worn or damaged, it is recommended to replace it.
Step 5: Remove the metal tubes connecting the valve to the exhaust and intake manifolds.. There are usually two metal pipes or hoses connecting the EGR valve to the exhaust and intake. Remove both of these connections using a socket wrench and the appropriate socket.
Step 6: Remove the EGR valve harness.. If your EGR valve has a harness attached to the sensor on top of the valve, remove that harness.
If your vehicle has an EVP shutoff solenoid that is not on top of the EGR valve, disconnect any wires or harnesses attached to that solenoid.
To remove the strap, carefully pry up on the end of the clip or press the tab to release the strap.
Step 7: Remove the EGR valve. The EGR valve can be attached to one of three areas:
Engine block (usually at the rear of the car).
Cylinder head or intake manifold (usually near the alternator or water pump before the engine).
Bracket attached to the firewall (this is usually for EGR valves with the EVP shutdown solenoid disconnected, to which the vacuum line is also connected).
To remove the EGR valve, you will need to remove two mounting bolts, usually the top and bottom. Unscrew the top bolt and remove it; then unscrew the bottom bolt until it loosens. Once it loosens, you can turn the EGR valve to make it easier to remove the bottom bolt.
- AttentionA: If your vehicle has an EVP shutoff solenoid that is not attached to the EGR valve and you are also not replacing your EGR valve, you do not need to remove the EGR valve at all. Simply remove the solenoid component and replace with a new block. You can then proceed to reconnect all connections and test the repair. However, if your vehicle has an EVP shutdown solenoid that is actually attached to the EGR valve, skip directly to the next step.
Step 8: Clean the EGR valve connection. Since the EGR valve has now been removed, this is a great opportunity to clean up the area, especially if you are going to be replacing the entire EGR valve.
This will ensure a secure connection and reduce leakage.
Using carburetor cleaner, dampen a shop rag and clean the outer and inner edges of the port where the EGR valve was attached.
Step 9: Replace EVP Shutdown Solenoid. Once you have removed the EGR valve from the vehicle, you will need to remove the EVP shutoff solenoid from the EGR valve and replace it with a new one.
Most EGR valves have one screw and clip that holds this assembly to the EGR valve. Remove the screw and clip to remove the old block. Then install the new one in its place and reattach the screw and clip.
Step 10: If necessary, install a new EGR valve gasket to the EGR valve base.. After you have removed the old EVP shutoff solenoid, remove any residue left from the old EGR valve gasket and replace it with a new one.
It is best to apply silicone to the base of the EGR valve and then secure the gasket. Let it dry before continuing.
If your vehicle service manual says you don't have a gasket, skip this step and go to the next one.
Step 11: Reinstall the EGR valve.. After installing a new EVP shutdown solenoid, you can reinstall the EGR valve.
Reinstall the EGR valve to the appropriate location (engine block, cylinder head/intake manifold, or firewall bracket) using the top and bottom mounting bolts you removed earlier.
Step 12: Connect the Electrical Harness. Whether it is connected to the EGR valve or the EVP shutdown solenoid, reconnect the wiring harness by pushing the connector back into place and securing the clip or tab.
Step 13: Connect the exhaust and intake pipes.. Install the metal connections of the exhaust and intake manifolds back to the EGR valve and secure them.
Step 14: Connect the Vacuum Hose. Connect the vacuum hose to the EGR valve.
Step 15 Replace any covers or other parts that were previously removed.. Reinstall any engine covers, air filters, or other components that needed to be removed to gain access to the EGR valve.
Step 16: Connect the battery cables. Once everything else is assembled, reseat the battery cables to bring power back to the car.
Part 2 of 2: Repair Check
After replacing the EVP shutdown solenoid, you will need to start the vehicle and reset all error codes before completing a test drive.
If the Check Engine light comes back on after clearing the error codes, check the following:
Inspect the hoses attached to the EGR valve and EVP shutdown solenoid to make sure they are secure.
Inspect the EGR valve mounts to the exhaust and intake manifolds to make sure they are secure.
Make sure all removed electrical components are properly installed. If the engine starts normally and no error codes are displayed after resetting them, perform a standard test drive as described below.
Step 1: Start the car. Start the engine and let it warm up to operating temperature.
Step 2: Check the toolbar. Make sure the Check Engine light does not come on.
If this is the case, you should turn off the vehicle and perform a diagnostic scan.
Error codes should be cleared on most vehicles after completing this service.
Step 3: Test drive the car. Take the car for a 10 mile road test and then return home to check for leaks or error codes.
Depending on the make and model of your vehicle, replacing this component is usually fairly straightforward. However, if you have read this manual and are still not 100% sure that you can do the job yourself, or prefer having a professional do the repair, you can always ask one of AvtoTachki's certified mechanics to come and complete the replacement. EVP shutdown solenoid.
