97 w/ a P0505 Code :(

[Deadly Sushi]

CRAP! Just got a P0505 Idle Air Control code and I dont know what to do.
Runs fine. Everything SEEMS fine. At idle the steering wheel vibrates quite a bit.

What should I do? And can anyone even tell me WHERE the IAC is on this thing?

[Kiwi-Corolla]

The IAC valve is found underneath the throttle body. Remove the throttle body and you'll see 4-screws underneath. Undo these (apply a fair bit of force so you don't round the heads) and you'll easily be able to get in there and clean it with carb cleaner.

[Deadly Sushi]

Originally Posted by Kiwi-Corolla

The IAC valve is found underneath the throttle body. Remove the throttle body and you'll see 4-screws underneath. Undo these (apply a fair bit of force so you don't round the heads) and you'll easily be able to get in there and clean it with carb cleaner.

so youre saying that I can CLEAN it and might be OK?
How hard is it to take off the Throttle Body?

[Kiwi-Corolla]

Originally Posted by Deadly Sushi

so youre saying that I can CLEAN it and might be OK?
How hard is it to take off the Throttle Body?

Yeah, it's worth a shot. Not sure if a dirty IACV would cause a code to activate as I'm not too familiar with the OBD-II system, but it's a good idea to clean it regardless. Be sure to reset the code by disconnecting the negative battery cable for a least 5-minutes after you've cleaned it. If that doesn't cause the code to go away then I'd suggest replacing the whole IACV unit with one from a junkyard or a brand new one from a dealer.

Before removing the throttle body however, check that the electrical connector for the IACV is plugged in tight. A good way to test that the connector is receiving power is to check that the middle terminal is receiving battery voltage with the ignition switched to 'ON'. You should also measure the resistance between the middle terminal and each outer terminal of the connector by using a digital multimeter. It should measure between 19.3 to 22.3 ohms.

Removing the throttle body is an easy procedure. First you start by removing the air intake hose that leads from the airbox to the throttle body. Simply undo the hose clamp and slide it off (the airbox doesn't have to be removed). Then disconnect the electrical plug for the throttle position sensor (black unit on the rear of the throttle body) and the plug for the IACV. Then remove the coolant hoses from the bottom of the IACV. They'll simply pull down when you release the clamps (just make sure they stay standing upwards so you don't lose any coolant). Once that's done, open the throttle by hand by pulling the lever and slip the accelerator cable out (if it's an automatic, also remove the kick-down cable). Now you can remove the nuts holding the throttle body on. There are to nuts and two studs. All you have to do is remove the two nuts, then remove the support bracket and the throttle body will slide right off.

It sounds like a lot of work, but it really isn't. It'll all make sense when you see it. Shouldn't take you any longer than 15-minutes to get it out. As mentioned earlier, just be sure to keep the coolant hoses poking upwards so that you don't lose any coolant. It might pay to label the hoses "1" and "2" so you know which one goes where when reconnecting them afterwards. You may find it easier to practice on a Corolla at a local junkyard if you have one near you. If you have any questions, just ask

[Deadly Sushi]

Originally Posted by Kiwi-Corolla

Yeah, it's worth a shot. Not sure if a dirty IACV would cause a code to activate as I'm not too familiar with the OBD-II system, but it's a good idea to clean it regardless. Be sure to reset the code by disconnecting the negative battery cable for a least 5-minutes after you've cleaned it. If that doesn't cause the code to go away then I'd suggest replacing the whole IACV unit with one from a junkyard or a brand new one from a dealer.

Before removing the throttle body however, check that the electrical connector for the IACV is plugged in tight. A good way to test that the connector is receiving power is to check that the middle terminal is receiving battery voltage with the ignition switched to 'ON'. You should also measure the resistance between the middle terminal and each outer terminal of the connector by using a digital multimeter. It should measure between 19.3 to 22.3 ohms.

Removing the throttle body is an easy procedure. First you start by removing the air intake hose that leads from the airbox to the throttle body. Simply undo the hose clamp and slide it off (the airbox doesn't have to be removed). Then disconnect the electrical plug for the throttle position sensor (black unit on the rear of the throttle body) and the plug for the IACV. Then remove the coolant hoses from the bottom of the IACV. They'll simply pull down when you release the clamps (just make sure they stay standing upwards so you don't lose any coolant). Once that's done, open the throttle by hand by pulling the lever and slip the accelerator cable out (if it's an automatic, also remove the kick-down cable). Now you can remove the nuts holding the throttle body on. There are to nuts and two studs. All you have to do is remove the two nuts, then remove the support bracket and the throttle body will slide right off.

It sounds like a lot of work, but it really isn't. It'll all make sense when you see it. Shouldn't take you any longer than 15-minutes to get it out. As mentioned earlier, just be sure to keep the coolant hoses poking upwards so that you don't lose any coolant. It might pay to label the hoses "1" and "2" so you know which one goes where when reconnecting them afterwards. You may find it easier to practice on a Corolla at a local junkyard if you have one near you. If you have any questions, just ask

You rock man! OK! Im off to try it.... wish me luck!!

[Kiwi-Corolla]

Originally Posted by Deadly Sushi

You rock man! OK! Im off to try it.... wish me luck!!

Good luck!

[speedy25]

If it set off a code its probably bad. I'm guessing you either find its not plugged in properly or fails the resistance test.

-SP

[Deadly Sushi]

I have noooooooo idea how to check resistance and stuff. Im not an electrical guy.

I looked at the engine and I dont know what the damn IAC looks like.
Im a loser.

[Kiwi-Corolla]

Originally Posted by Deadly Sushi

I have noooooooo idea how to check resistance and stuff. Im not an electrical guy.

I looked at the engine and I dont know what the damn IAC looks like.
Im a loser.

Checking the resistance is simple. All you have to do is buy or borrow a digital multimeter and follow the instructions (either online or in the provided manual). Multimeters are very handy to have, so you're bound to use it later in life at some point.

You're not a loser. The IAC valve is a tricky thing to see at the best of times. Here's some photos I just scanned from my Gregory's manual to show you where the IACV plug is that you have to disconnect to check for resistance (photo #1), and what the actual IACV looks like (photo #2). I've marked both with a red arrow so it's easy to identify:

[m_wnzl]

Im surprised nobody has mentioned about cleaning the iacv/circuit with the engine running. Take your can or carb or throttle body cleaner with the skinny tube attached to the nozzle, give the engine a rev shoot the cleaner directly into the iacv opening. Before the engine bogs down completely, stop spraying and crank the throttle open to overcome the flooding condition you just caused and just as the engine recovers do it a couple more times. You can also spray into the intake with the same procedure to help clean some of the gunk out too. But I do recommend that nobody hangs out back by the tailpipe.