Engine code p0505 idle contol valve help

code p0505 idle contol valve help

I keep getting code P0505 for the idle control valve. I took the valve off and it opens and closes. Does anyone else know what to look for? When I turn the key to on I can hear a buzzing noise from the valve. Is this good or bad? The car is a 2001 Corolla. Also when I start my car sometimes it idles really high and then almost dies for a second like its trying to idle down.

its probably the one under the butterfly or throtlle body...whatever you call it..

Try disconnecting the ECT sensor (same side as the throttleb body - right into the side of the head) and see if the valve opens when the ignition is turned on. If it doesn't move - then you have a bad control valve.

Make sure that everything else is OK - sometimes a loose vacuum hose or dirty MAF sensor can also spawn unrelated CEL codes. Don't want to start swapping parts until you get the problem properly diagnosed.

The MAF sensor was cleaned and all vacuum hoses are connected. I took the whole idle air control valve off the car and and it opens when the ignition is turned on. Although I'm not sure how far it is supposed to open/close.

As long as it is moving - then it is OK. I'd start checking other areas for the weird idle - throttle body need cleaning? Clogged PCV valve. How does the A/C work - any squealing belts?

An IAT issue could be true - if you had an Echo or Scion xA or xB - I've read all kinds of issues with their IATs. But on the Corolla - this is the first for an 8th gen that I've come across - the only other was an early 9th gen with some other issues. That guy replaced his IAT for about $400 CND - problem went away for 6 months then came back.

I'd make sure to rule everything else out first - before I tank the IAT valve.

The throttle body and intake is all clean. I put another engine in my car and the engine before was doing the same thing so I think it's something on the intake because that's one of the only things I didn't replace.

Hmm - could be a vacuum leak somewhere along the intake runners, airbox into the TB, or the intake manifold mating surface to cylinder head. Try putting some water into a spray bottle or a solvent of your choice (just keep it away from materials that it will eat) and spray suspect areas. If the idle improves temporarily - then you just found the leak.