Toyota Rav4 P0505: Idle Air Control System- Failure

P0505 An OBDII Code that addresses the idle air control system within the Toyota Rav4.  It’s a generic code, which means that it has the same meaning for the Rav4 as it would any other vehicle (Rav4 or not).

P0505:  Idle Air Control System:  Malfunction

P0505 triggers when there is either a stuck or clogged idle control valve, as well as a vacuum leak.  Other causes can also be involved.  Although, they aren’t as prevalent.

P0505 Symptoms:  Toyota Rav4

This particular trouble code lets you know that there is something wrong with the idle air control system, but that’s about it.  The symptoms may vary.

These are the top symptoms of P0505.

• Engine service engine will soon be light
• Don't be rough
• Stalling
• Very high idle speed 

Rav4 Causes P0505

P0505 can usually be caused either by a vacuum leak or an issue with the idle control valve.  While replacing the idle air control valve seems like a good idea, it’s worth your time to check for a Vacuum leak first.

Valve for Idle Air Control

The idle air control valve’s primary job is to regulate the idle speed of your engine.  This is done by making sure that the engine's idle speed is maintained at the correct level.

You can either get the IAC valve stuck or dirty.  The IAC valve may require a replacement or cleaning may suffice.  Here’s a great Video from YouTube How to clean an idle air control valve  

They are available if you decide that an idle valve control valve is needed. It is very affordable.

Vacuum Leak

While the idle air control valve is often the cause of P0505, it’s a great idea to start diagnosing it by looking for a vacuum leak.  Examine the vacuum tubes near the IAC.  It may be necessary to replace them if they appear cracked or dry-rotted.

You can code the Rav4 with leaks in your intake and around the throttle bodies.  Here’s a great article from Popular Mechanics on How to locate a vacuum leak.

Carbon Buildup

Carbon buildup can occur around the IAC's inlet.  The problem can be fixed by inspecting the IAC area for carbon-blockage passages.

It can cause the intake of air to be reduced if the throttle body becomes too dirty.  You can even throw P0505.  Often, when this is the case, you’ll feel the engine stall for a second before it recovers when slowing down.  

This happens because the engine can’t adjust to this problem fast enough.  This problem is usually solved by cleaning the area around the throttle blades.

Conclusion

You will be able to diagnose P0505 on your Rav4.  Most of the time it’s a vacuum leak or the idle air control valve.  If you feel like there’s anything that you can add, please feel free to leave a comment below.