Updated at: 13-08-2022 - By: Lucas

One of the most critical parts of a car’s engine is the idle air control valve, or IAC valve. The IAC’s primary function is to smooth down the engine’s idle by controlling the amount of air it receives.

Engine damage can result from difficulties with the IAC valve. When the engine is off and the throttle is not being utilized, the valve is in charge of controlling airflow.

If this airflow is not properly managed, it might cause stalling, poor acceleration, and the engine light to come on. We’ll go through how to identify if your idle air control valve has an issue and show you how to reset it quickly and efficiently in this article.

In order to reset the idle air control valve, turn the car on and put it in park, then push the gas pedal down for about 5 seconds while counting down, then turn the car off, wait a few seconds, and then turn the car back on to see if it is idling properly again.

What Is An Idle Air Control Valve?

How Do I Reset My Idle Air Control Valve

One of the most common engine components is the idle air control valve, which may be found linked to the throttle body. Idling airflow is controlled electrically by the IAC and the vehicle’s ECU.

A car’s IAC valve keeps injecting air even when the throttle plate is closed, ensuring smooth operation even when the engine is off.

Because of its design, the IAC bypasses the throttle plate, allowing for smoother idling and more efficient combustion.

It’s vital to note that the ECU plays a part here as well. The IAC valve receives a signal from the computer system when the vehicle is parked or stopped. It is the valve’s job to adjust to allow for adequate combustion airflow once an electrical signal has been received by the valve.

How Do I Tell If My Idle Air Control Valve Is Bad?

As you can see, a properly working IAC valve is critical to the overall performance of your engine. The valve will keep the correct amount of air circulating when the car is idle and the throttle plate is closed.

However, occasionally you may notice your car is not idling as smoothly as it used to or your check engine light is on and you don’t know why. Idle air control valve problems might be spotted by looking for these two indicators.

Here are a few more indications that your IAC valve may be failing:

  • Rough idling (car engine doesn’t feel as smooth when you are stopped).
  • Poor acceleration. 
  • ‘Bursts’ in idle speed – the speed randomly fluctuates when the engine is idle. 
  • Stalling. 
  • Increased RPMs when the vehicle is idle.
  • Check Engine light is on. 

In the event that your car’s idling is off, you run the risk of doing major harm to the engine. But keep in mind that the symptoms described above could also indicate other engine problems.

It’s usually better to consult a medical practitioner when there’s any doubt about the IAC valve’s functionality. For the most accurate diagnosis, you’ll need a specialist, however you may test and reset your IAC valve yourself if you’d rather.

How To Reset IAC Valve – A Step-By-Step Guide

How Do I Reset My Idle Air Control Valve-2

Troubleshoot and confirm that your vehicle’s idle air control valve is the source of any performance issues if you detect any of these symptoms. A short test of the IAC valve can reveal whether or not it’s working properly before you hurry to reset it,

The IAC valve test can be performed in a few simple steps.

Step 1

You want to hear clearly, so turn off both the radio and the air conditioning.

Step 2

While the automobile is idling, pay attention to the sound of the engine.

Step 3

Take a look at the vehicle’s RPMs and write them down. This number should not go below 600 or rise above 1000.

Step 4

If the car’s RPMs are low, it could mean that the IAC valve is malfunctioning or that there is a vacuum leak somewhere in the vehicle.

You can try to reset the IAC valve if an issue is found after testing the valve. Even though it is not a long-term solution, resetting the valve may be all you need to keep your IAC running until you can get it repaired or replaced.

Resetting The IAC Valve

Here is a step-by-step guide to resetting the IAC valve if you’d want to give it a go.

Step 1

Set the ignition to “ON.”

Step 2


Step 3

Now, softly depress the gas pedal.

Step 4

Afterwards, when you’ve let off of the pedals. You can now simply leave the car in “On” mode for about five seconds.

Step 5

Next, turn off the engine and let it sit for about 10 seconds before starting it again.

Step 6

It’s time to restart the automobile and make sure it’s idling properly.

How To Clean IAC valve

How Do I Reset My Idle Air Control Valve-3

It is possible that an IAC valve is malfunctioning because it is unclean and needs to be cleaned.

The IAC valve can become clogged with carbon and debris during combustion. The idle air control valve (IAC) may malfunction if it becomes contaminated with debris.

Getting rid of any accumulated gunk or pollution might help you get the IAC valve functional again. If you’re going to clean the idle air control valve, be sure to consult your owner’s manual beforehand.

You don’t want to do any more harm, so consult your owner’s manual for instructions on how to properly clean the valve.

However, if you are unable to locate the necessary details, the following is a step-by-step guide for cleaning the IAC valve on the majority of automobiles.

For your own safety, you should only use these goods if you are sure they won’t cause any harm to your vehicle or its components.

Step 1

You need to find the idle air control valve. The IAC is often located next to the engine’s intake manifold on the left side of the engine bay.

Step 2

Remove the plug from the IAC valve’s backside next. You should be able to plug in the plug with a screwdriver and no further tools.

Step 3

The screws and bolts that were used to secure the valve in place must be removed at this point..

Step 4

You can now see the valve, which should be facing downwards, because the bolts have been removed.

Step 5

Spray the pointed end of the valve with a carburetor cleaner. Avoid getting any of the cleaners into the valve’s housing, as this could result in damage.

Step 6

The valve should be sprayed until all of the carbon and other material has been removed from it.

Step 7

Fix the wiring and plug it back in before putting everything back together.

Step 8

You can now start the car and listen to how it idles after everything has been reinstalled correctly. If dirt was the problem, you should hear a difference now.

The IAC valve can be cleaned by removing it, as demonstrated in this guide. Several web tips explain how to clean the idle air control valve without removing it.

Is your learning style more visual?

If your car’s IAC isn’t working properly, you can watch this video guide to learn how to clean it.


How do you check a bad IAC valve?

If you’re concerned about any aspect of your car’s engine, it’s always advisable to consult a professional. You can, however, perform a self-test of the IAC valve by just starting the engine and listening to the engine noises while the vehicle is still.

Valves can malfunction, making the engine’s idle seem unnaturally quick or slow. The RPMs while the automobile is idling must also be recorded, and this number should be between 600 and 1000 if there is a problem.

It’s also a good idea to look for the IAC in the engine to see if it’s stuck or clogged with dirt or carbon.

How do you test the IAC valve?

Turn on your automobile and listen to the idling engine to see if the IAC is working properly. When a valve is working properly, it should have a consistent and smooth sound. The symptoms of a malfunctioning IAC valve include stalling, poor acceleration, increased RMP, and erratic idling. It is crucial to be aware of these.

What happens if you unplug IAC?

The IAC can be disconnected when the engine is idle without causing any harm. It’s possible that disconnecting the IAC valve could have negative impacts on the engine’s performance, but it’s necessary to maintain the air flowing when the engine is idle.

Can the idle air control valve be cleaned?

Yes, the idle air control valve may be cleaned. By detaching it from the throttle body or cleaning it while still in place, the part can be cleaned.

If you’re trying to get rid of carbon and debris, you’ll want to exercise caution while selecting cleaning products. This article includes a how-to for cleaning an idle air control valve.


In a car’s engine, the IAC valve is a critical component. During idle, the idle air control valve regulates engine airflow by controlling the amount of air that is drawn into the combustion chamber. The IAC valve is responsible for the smooth operation of your car’s engine when you put it in park.

Despite the fact that the valve is designed to endure the whole life of your car, damage and debris can occasionally cause problems. It’s a good idea to check the IAC valve if you discover your automobile isn’t idling properly.

Here, we’ve explained how to reset and clean the IAC valve to get it running again. Mechanics may be necessary if you continue to have issues when your automobile is idle.