Nissan Frontier P0505: Idle Air Control System- Malfunction

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

P0505:  Idle Air Control System:  Malfunction

P0505 usually occurs due to a stuck idle valve, a blocked idle valve control valve, or an unattended vacuum leak.  However, there are other possible causes.  Although, they aren’t as prevalent.

P0505 Symptoms:  Nissan Frontier

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.

• Soon, Service engine light
• It is a rough idle
• Stalling
• Very high idle speed 

Frontier P0505 Causes

P0505 will usually indicate a vacuum leakage or an idle air control valve problem.  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.

It is possible for the IAC to become stuck or dirty.  It may be necessary to replace it or clean it.  Here’s a great Video from YouTube How to clean an idle air control valve  

You may need to replace your idle air valve if you feel it is time. 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.  Check the vacuum tubes surrounding the IAC.  It may be necessary to replace them if they appear cracked or dry-rotted.

You can code the Frontier by leaking around your throttle body, intake leaks and other leaks.  Here’s a great article from Popular Mechanics on How to spot a vacuum leak.

Carbon Buildup

Carbon buildup can occur around the IAC's inlet.  It is possible to fix this problem by checking the IAC inlet area for blocked 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.  It is possible to fix the problem by simply cleaning it from around the throttle blades.

Conclusion

It's possible to find P0505 within your Frontier.  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.