Car is Idling high (1500rpms) then I get a P0505 code from my IAC. Just replaced it wanted to see if I might need to have my car relearn my Idle or if that would not cause the code to come up?


If relearning the Idle doesn't work I am going to try troubleshooting the IAC, wiring harness, and PCM like below..


P0505 IAC (Idle Air Control) System Malfunction


After that then looking for vacuum leaks. Anyone had similar issues or any advice?

 

pretty common issue and ends up being the IACV

Very finicky on these cars, i'm sure a quick Google search with site:acurazine.com would yield MANY hits. I'd replace the IACV or try and clean it (I've tried to clean multiple times and it never really fixed the problem so I'd recommend the former.

 

Yea I am seeing that this is a common issue, every post I come across seems to be exactly like the problem I have, but no one posted how they fixed their issues, the thread just goes cold.


In terms of IACV, do you think it could be faulty even though it was just replaced? Could it even be a wiring issue? Do you think relearning my idle could solve this or is it going to more than likely be a problem with my IACV system?

 

Civic.. Didn't you have this problem a long time ago? Was it your runners that was an issue?

 

if it's recently been replaced, I'd make sure there's no air bubbles in your coolant lines as that could cause a code as well

 

Ahh that could be it. dealer told me my radiator fan was cutting out and that I could have air in the system.. bleed the system?

 

Sounds like you're on to something!!

bleed or just 'burp' it:

 

This is very helpful thanks thoiboi! Gonna give this a shot tonight and see if this fixes it. If I just took off my P2R spacer, would you reset the ECU and let it relearn the idle just to be sure or should it adjust pretty quickly?

 

^^
Just used one of those systems when changing my radiator hoses (the originals were getting a bit dated so it's better to replace them than have them fail). Worked really slick. No need to do the constant fill and run and burp and fill. Just put the adapter cap on, fill the reservoir and then run the car for a bit until the thermostat opens and let it run a bit more while making sure the reservoir stays full to keep any air from getting in. When you're done, everything is nice and filled to the top.

Can't hurt to reset the ECU. Force it to relearn rather than hope for it to take notice and relearn.

 

I'm looking around near me and it doesn't look like anyplace is going to have this funnel, not even harbor freight. Its not required right? Just makes it easier? Can I use a regular funnel?


Also just to make sure I have it down right to bleed system. (Never actually done this before)


1. turn heat on and fan off
2. loosen bleeder
3. add mixed coolant to system until it comes out of the bleeder.
4. tighten bleeder
5. run car at 2500rpms with radiator cap open and funnel in until it is at operating temp.
6. top off radiator and reservoir
7. close it up and its ready to go




Is that it?

 

Ok update. Couldn't find the bleeder bolt for the life of me. Opened the radiator cap, started the car and the fluid was at the brim. Then elevated the car so the radiator was the highest point started it again and it dropped about a 1/4 or an inch to maybe a 1/2. So it looks like there was air in the system.


Driving back looking at my RPMs when I put the clutch in they are bouncing between 1100-1300 for about 30 seconds and then levels off at about 900 rpms at idle. Looks like there is a vacuum leak somewhere.


This morning when it was at its worst, I would be driving and let off the gas and the car would get jerky, until I opened the throttle more and let more air in. Does it seem like air is getting into the system behind the throttle somewhere?

 

From 01 cl owners manual.




By definition vacuum leaks are always after TB.

 

Interesting so there is no bleeder? Or is that the drain bolt that it is talking about in step 6?


Thanks for this by the way!

 

Yes drain bolt for draing the block.

 

Be sure you only install the r cap half way the first time, not all the way... ref step 10 or else you will get burn opening it to top off cooland.

 

So the only way to get air out is elevation method or the above method?

 

Ahh no. Some better shop will use the vacuum method.

They will suck down the cooling system and hold it under vacuum and then introduce the coolant. Probably the best way.

 

I got mine from Amazon:

 

Gotcha. I will have to look into that then. Looks like the air that I did get out has stopped it from idling high and throwing a P0505 code, but its surging between 1000 and 1300 rpms. I will see if I can identify where the leak is coming from tonight with some spare tubing and a nail to clog the tube. So I should be checking any hose past the throttle towards the manifold? If it is not a hose issue but maybe a manifold leak is the best way to tell with card cleaner to see if it chokes?





Thanks thoiboi, I'm definitely going to need this for later

 

There is no bleeder, per se, as you would find on my 01 Olds Alero along the front of the engine, easily accessible at the top of the valve cover, near the coolant reservoir. Step six is to drain the entirety of the block, IF you desire to perform this step.

o1acls' depicted information is correct; however, the step where the owners manual states to: Turn the ignition switch on to (II). Set the climate control system to 90F. Then turn ignition switch off. Was cut off; but, you know about this already.

Personally, I have just used the method given in the owners manual. Furthermore, during step 11, I usually cycled through a few rounds of finger pinching the upper rad. hose (on/off) to help facilitate the bleeding of any remaining air. YMMV.

 

 

Ok thought I would give an update from last night. Ran by AutoZone picked up carb cleaner and check for leaks, no one there could help me figure out why it is doing this either. It got progressively worse yesterday with the idle surging. Was referred to a local guy that could take a look. Stopped by right as he was closing he took out a sweet Snap-on scan tool tablet and hooked it up to my ECU and reset all the sensors and EVERYTHING on my car. Idle surging Immediately stopped surging.


Drove it home and noticed that the idle wasn't surging but was idling high at 1200rpms. Came to a stop light and reved it a little bit and it immediately started surging again. Got back to my place let the car cool down and then went out there with a hose testing for vacuum leaks again.


Thought I found one on the hose that runs parallel to the top of the manifold near the fire wall. But didn't have a replacement so I just put it back on as secure as I could. I also started checking a couple other lines that had coolant running through them (WHOOPS!) Thankfully I was wearing gloves so I didn't scald my hand, but did have coolant come out everywhere.


So left the car there for the night. Got up this morning and ran it around town for about an hour, and NO PROBLEMS! Not idle surging and not running high like it should be this point. So either a hose was loose that I put back on tighter last night, or there was still air in my cooling system that can out when I ran the car an accidently opened a cooling line.


Gonna keep an eye on this for the next few days and see if anything comes back. Wanted to post up here so that if other people have the same issues they can see what worked for me.

 

Glad it worked out,

I'd opt for the air came out when you inadvertently 'bled' the system (in the unconventional way I might add )

The high idle at first after the reset is normal as part of the "Idle Relearn". Keep us updated Glad it wasn't the IACV after all! Saved you about $120 parts alone!

 

Thanks thoiboi!


Deff didn't mean to bleed the system like that and that coolant was REDICULOUSLY hot! Thankfully I had thick gloves on!! But I will keep everyone posted over the next few days and see what happens.


As for high idle after reset.. is it also normal to surge sum as well?

 

No, it shouldn't surge. There was still air even after the reset of the ECU, hence the surging. You fixed the issue afterwards and left it overnight so when you started it up again, it was fixed. If you want to reset your ECU on your own in the future, you can also just unhook the negative side of the battery for a few seconds (just make sure you have the radio code (if stock radio)).

 

Gotcha, Yea I will deff remember that. Thanks again!