Mazda 3 P0506: Idle Air Control – RPM Lower than Expected

P0506 It is the most common OBDII code. This code is usually triggered when engine idle speed falls below the limit predetermined by the manufacturer.

It's a generic cod, meaning it can be used to refer to any code. Mazda3 It will work as any other vehicle.

 P0506 Symptoms:  3

P0506 is most often visible while driving. These are some of the symptoms:

• Coming Soon: Service Engine Light– The reason why you are here.
• Lower idle speed– Assuming that the code has been thrown due to a legitimate issue, you should notice the engine running slower when not pushing the gas.
• Stalling–  The idle may be too slow for the car to run without pressing on the accelerator pedal.

Mazda 3 P0506 Diagnoses and Causes

Many possible causes of P0506 exist. While the code specifically mentions the “Idle Air Control System”, it would be a mistake to just go ahead and replace the idle air control valve without a little due diligence. It’s not always the cause of the code.

Below are some common problems with the Mazda 3's P0506, as well as how to fix them. Remember that different model years can cause P0506 symptoms. Start by searching for the a Leakage of vacuum You can then move on from there.

Vacuum Leak

Leaking vacuum systems can cause the engine to idle more often. The vacuum system can leak, which causes the combustion chamber to lose its air balance. 

How do you find a leak in your vehicle's vaccum? (Popular Mechanics, Article)
Find a Vacuum leak in under a minute (2CarPros, YouTube)

Vacuum leaks can be caused by bad things vacuum hoseThe Take in a lot, EGR SystemYou can find it anywhere that air is flowing. It’s not hard to find a vacuum leak though. Use the resources above and you’ll find it in no time.

Valve for Idle Air Control

The majority of modern fuel-injected engine are fitted with an idle control valve. However, not all engines have an idle air control valve. If you have determined that you don’t have a vacuum leak, the IAC is a great second place to troubleshoot P0506.  You can find idle air control valves here It is very affordable.

How to diagnose an IAC valve (Autozone Guides)

Throttle body

In the course of an automobile's life, the throttle body will open and close millions of time. The accumulation of dust and air can slow down the body's ability to withstand high levels of pressure. The vehicle's idle performance can be affected by this grime. When dirty, you’ll often feel the vehicle almost stall before the computer compensates and opens it a little more.

If the throttle body is damaged or not functioning properly, then the code can be thrown.

Here are some signs your Throttle Body is failing and what to do (Repair Pal)
How to tell if your throttle is bad or dirty (YouTube Auto Repair Youtube)

Bloated Intake/Exhaust

The idle could drop to P0506 due to a problem with the catalytic convert or the intake manifold. 

Conclusion

The P0506 problem is serious. Your engine can stop at any moment, making it dangerous to drive. We suggest that your 3 be serviced ASAP. You're welcome!