Ford F150 P0506: Idle Air Control – RPM Lower than Expected

P0506 This is an OBDII common trouble code. It's usually caused by an engine speed that is below the manufacturer-predetermined limit.

This is known as a generic code. It has the exact same meaning regardless of whether it's used for another purpose. Ford F150 As it would for any other vehicle.

 P0506 Symptoms:  F150

P0506 is usually not noticeable while driving. The F150 has the following 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.

Ford F150 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 Ford F150's P0506, along with how to resolve them. Remember that model years can vary. Start by searching for the a Vacuum leak You can then move forward.

Vacuum Leak

The F150 will idle more often if the vacuum system leaks. Leakage of the vacuum system causes the combustion chamber's air balance to be thrown off-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)

Bad things can cause a vacuum leak vacuum hoseThe Intake is endless, 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

Modern fuel-injected engines have an idle air 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.  The idle air control valves can be found here Very affordable.

How to diagnose an IAC valve (Autozone Guides)

Throttle Body

The throttle body can be opened and closed millions of times during the lifetime of a car's engine. 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.

Alternativly, the throttle body may have been damaged and may stop regulating the airflow properly. In this case, the code could 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)

Blockage of Intake or Exhaust

It could be a problem in the catalytic converter or an obstruction to the intake manifold. This can lead to idle dropping and throwing P0506. 

Conclusion

The P0506 problem is serious. We recommend that you have your F150 serviced immediately to avoid the danger of an engine that could stall. You are welcome!