Modern cars are complex machines with so many different parts working together. Staying on top of repairs in such complex systems is made easy by the use of OBD II standard and check engine light codes. 

Today we’ll take a look at the P0507 code that often comes online when your car experiences idle control issues. We’ll try to explain the code best as we can, help you properly diagnose it, and take you through the steps that could potentially help you fix whatever is causing the code. 

What Is the P0507 Code, and What Does It Mean?

The P0507 code is an idle RPM sensor control code. It occurs when the actual idle RPM is higher than it is supposed to be. The ECU (or PCM) constantly tracks what’s going on with the engine.

This includes monitoring the idle RPM as one of the metrics. Every car has a predetermined RPM range that the ECU finds acceptable. Once the RPM values go above or below that range, you’ll get the P0507 code. 

How Does the Engine Maintain Idle? 

An engine maintains idle using a valve that allows air to bypass the throttle body. In this way, you don’t have to press the pedal for the minimum amount of starting air to flow into the engine.

Modern vehicles use an ETC (electronic throttle control) system. Although some still use a traditional throttle control system, as it is cheaper, it’s always up to you to use your owner’s manual to check which system you have.

What Is an Idle Air Control Valve?

The IAC, or idle air control valve is the small bypass valve we mentioned previously. It allows the engine to run (idle) without you having to activate the throttle body and open the butterfly valve a tiny amount to keep the engine running. 

How Do I Reset My Idle Valve?

Although many people will say that an idle valve can be reset in a correctly functioning system, it should not need to be reset. There is no way to “reset” an idle valve.

A much easier solution is to remove the small idle air controller and just give it a quick clean. It’s not advisable that you soak it in water as it uses an electrical solenoid, however, you can just take a tube cleaner or toothbrush and clean the valve. Carbon cleaner will work just as well.

What Causes P0507 Code?

If we look at the systems that are linked to engine idle, we’ll find that more factors affect this basic parameter than one might think. Here is a list of common causes that can trigger a P0507 code and cause your car to idle out of range. 

• Vacuum Leak
• Throttle system failure
• Damaged Idle air controller (IAC) 
• Exhaust issues
• Circuit Damage

Vacuum Leak

A vacuum leak can cause an unmeasured amount of air to enter the intake system. If the leak occurs between the MAF sensor and the throttle body, the ECU won’t be aware of the additional air in the system. 

It will then struggle to compensate for the unusual air/fuel mixture by increasing or decreasing the amount of fuel that is injected into the intake. This will usually cause idle issues that can trigger the P0507 code. A vacuum leak is one of the most common reasons why your idle is abnormal. It also happens to be one of the cheapest things to go wrong and cause a P0507 code. 

Throttle System Failure

The throttle body controls the amount of air flowing into the engine, which controls engine speed. When your vehicle is on, it lets a specific amount of air through which allows for the vehicle to idle.

Additionally, the cable that controls the throttle, actuator, air intake housing, or the throttle control module can fail. This all depends on your vehicle as some use a throttle-by-wire system and have an integrated module, so it’s always best to consult your owner’s manual to learn which of these components are in play with your particular vehicle. .

If any of these components malfunction, the vehicle may stall or idle too high. That, in this case, will cause the P0507 code. 

Damaged Idle Air Controller (IAC) 

If the main valve is responsible for idle malfunctions, it will affect your idle RPM. In some cases, this can cause stalling, and in some the P0507 trouble code.

Constant air flowing into the valve through the air intake and the back draft of air can cause the valve to become clogged. Now, because the valve is controlled electronically by a solenoid, it can burn out and cause the valve to malfunction.

This problem is particularly prevalent in cars that use direct injection where soot commonly returns through the PCV system.

Exhaust Issues

The O2 sensors use the composition of exhaust gases to tell the ECU how efficient the combustion is. Incorrect readings caused by exhaust issues can lead to a change in the fuel trim. If the ECU goes wide with its compensation, it could cause the engine to run rich or lean, at which point one of the side effects is a rough idle. 

Your engine computer will then adjust the idle so that the vehicle doesn’t stall. Of course, the difference in RPM causes the P0507 code.

What Are the Common Symptoms of P0507 Fault Code?

While there is a wealth of issues that can cause this trouble code, the symptoms are few. This is mainly because the trouble code is so specific. The two main symptoms are:

• High or rough idle
• Check engine light

High or Rough Idle 

As the code is specifically related to the idle being high, it makes sense that your vehicle idling high would be a symptom of the trouble code. Of course, you’ll be able to hear when the idle RPM is higher than usual, and the RPM needle will settle higher than it usually does.. 

That being said, a rough idle is also a symptom to look out for. A rough idle is common with issues such as vacuum leaks where the ECU struggles to read consistent data and apply a stable fix in the form of a fuel trim adjustment. 

Check Engine Light

If you can’t tell whether you have a high idle, the check engine light is another indicator that you have a problem. It doesn’t point directly to the P0507 code, but will help recognize that there is an issue.

How to Diagnose and Fix the Cause of P0507 Code 

Diagnosing a P0507 can be a tedious process because there are so many engine issues that can also cause a higher idle. However, once you’ve solved the more prominent ones, you should be able to fix the overall issue fairly quickly.

OBD II Reader

First thing first, run a full scan of the car using an OBD II reader. This is pretty much the first step of any diagnostic process when you have a check engine light on the dash. The OBD II reader allows you to interact with the PCM and perform conclusive diagnostic tests.

Once you’ve run your scan and determine that you’re dealing with a P0507 code, you can now test the throttle actuator and body. If those are functioning correctly, we can move on to more direct diagnosis methods.

Check for Obvious Issues 

Most engines utilize a maze of vacuum hoses and airways to run. If any of these gets undone by accident, or if it cracks, you’ll have a vacuum leak on your hand. While vacuum leaks aren’t always obvious, as we’ll discuss just a bit further down, they sometimes can be. 

It’s generally a good idea to begin a more thorough diagnostics process by giving all of these vacuum hoses a quick look. Try to spot any hoses that have come loose, or disconnected. Look for hoses with an obvious crack, usually where the hose bends. Check the intake pipe for cracks, loose clamps and similar obvious issues. 

Vacuum Leak

As we’ve concluded that a vacuum leak can cause a P0507 code, it’s only natural that we test for air leaks.

Your first instinct should be to hook up the vacuum tester to the air intake hose. Start your vehicle. It should be in neutral and the parking brake should be up, so the vehicle doesn’t move. Depending on altitude, you should get around 14-18hg.

A trick to diagnose where the leak is coming from is to use a spray bottle with some dish soap. You’ll see bubbles and foam forming up on areas where there is a leak. 

Throttle Body Issues

It is extreme to remove the throttle body completely first, as you can easily diagnose whether the inner components are functioning using the ODB II self-test.

If it is functioning, you need to divert your attention to the IAC. Of course, if your throttle is electronically controlled, testing will be slightly different.

When testing any throttle system, make sure that your transmission is in neutral, A/C is off, the parking brake is up, and your engine is warmed up. This is to prevent any damage to you or the vehicle. Some vehicles will have different requirements for you to conduct testing, so it’s always important that you follow the owner’s manual.

Now, use your multimeter and set it to ohms. As always, contact the positive probe to the sensor and the negative probe to the ground. Your vehicle has a cold and hot idle setting. When the vehicle is cold it should read between 17 – 25 ohms. At operating temperature, it should read between 21 and 30 ohms. Numbers differ depending on the sensor manufacturer.

Some vehicles use an ISC (Idle Speed Controller). This is the same as the IAC.

Does P0507 Clear Itself?

Once you’ve fixed all the issues, your code should disappear by itself. Of course, you’ll know when your vehicle is idling correctly, so you won’t have to clear the code once you give the-OK.

Is it OK to Drive with P0507?

Depending on the issue that you have, it may or may not be safe to drive with a P0507 code, as this error can be a symptom of a bigger issue. That being said, it is okay to drive a short distance with a higher idle than normal.

Use Quality Parts to Fix P0507 Code!

Often our first instinct when the check engine light illuminates is to panic. Luckily, the P0507 code is not the most serious. It does, however, mean that you might need to replace a component or two, or you might need to use some elbow grease to get rid of it. 

Our easy-to-use website, eEuroparts.com, has all the parts you’ll need to fix an idle issue on your European vehicle. To find what you’re looking for, simply select your car from the drop-down menu and choose the parts that you need from our comprehensive offering.