P0505 = Idle Control System Malfunction

 

Am I missing something? Yes, but I believe that if there was an O2 sensor problem, I would get an additional fault based on the O2 side.

 

correct an O2 sensor problem should throw it's own code.

I am not familiar with you vehical I just looked up the code in my data base.

 

Here is another flukey thing about this, that I have noticed in the last couple of days (after the pcv & breather). If the code gets set when I start up, it stays set and never goes out. But, if it does not get set when I start up, it never gets set during that trip.

So, today I turned the key and the check engine light came on long enough for it's check, then went off like the other indicator lights. Then I cranked it over and it did not come back on. I took it for a 20+ mile ride. During that whole ride, it never turned on. I turned it off, got something to eat, and hit the road again. It turned on when I turned the key and when the indicator light check was done, it stayed on. Then I started it up and it never went off. So, the light is coming on, and staying on, without starting the engine. But, not all the time.

If it were an intermittent problem, why wouldn't it turn on and off during the same ride. If it were an electrical short, it would also turn on and off during the same ride. And I have to wonder why it comes on and stays on prior to starting the engine. I think this is something electronic or electrical that is making the IAC not work properly.

One last thing. If I pull the negative battery cable for 20 minutes, and then reconnect, it does not turn on the check engine light the first time I turn the key. But, it will the next time.

I will check tomorrow if it has anything to do with engine temperature:
I'll pull the cable and let it reset.
I'll turn the key on but not to run and see if the light comes on.
If it doesn't, I will turn it off then back on again several times to see if it triggers the light on.
If not, I will drive it until it is warm, turn it off, then turn the key to on to see if it triggers.
Then I will disconnect the negative battery and do the reset again.
Lastly, I will reconnect the cable and turn the key to on again. If it triggers the light, first time, then I know that temperature has something to do with it.

 

Temperature has no effect.

I have combed through the Chilton's manual. From what I read, there is only two things that I need to do that I have not:

Check the wiring through the IAC circuit to make sure that nothing is shorting anywhere. This means taking the plastic conduit off of the wires (ych).If nothing is wrong there, the next step from what I can tell is to check out the PCM.

That brings me to my question. I took the van to Autozone and they had a scan tool, but it simply gave them a P0505 error, which I knew all along. Is there a scanner, that the dealership might have, that would give them more specific information? Or a way for Autozone or the dealership to check out the PCM without removing it?

Thanks for any answers.

 

Hi sharon. It sounds like your about ready to drive it off a cliff! First, a po505 is an electrical code that concerns only the IAC stepper motor, the wiring to it, and the pcm. cleaning the iac does nothing, the pcm is sensing an electrical fault, either open or short, in the wiring, pcm, or IAC motor(valve....). If you have replaced the IAC, was it from a Dodge dealer or Autostoned? I am a master a.s.e. and L1 advanced eng perf. certified mechanic and I don't send my worst enemies to autozone for electrical items!!! If it were my vehicle I would replace the IAC with one from Dodge and if you still have an issue check the wiring but don't forget to look at the terminals and connectors for any damage, corrosion, or backed out pins from unplugging and plugging them in! Good luck and remember if you cant dodge it.....ram it!

 

It was not a Dodge part, but I have heard from several people who had the same problem with a Dodge IAC.

I am taking the IAC back today, but wanted to ask you one question. The pintle on this IAC is fully extended, to the point where you can see the white inner shaft and the spring inside. Is this normal?

Thanks for your help.

[IMG]local://upfiles/48779/FB9C957A58234110BF8CA3D43525B3ED.jpg[/IMG]

 

I pulled a new one off my parts shelf ( I service approx. 50 dodge vans mostly 94-03's and i stock this part!!!)part #53032067AA and you cannot see the spring or shaft. Make sure you DO NOT TURN THE KEY ON OR ATTEMPT TO START VEHICLE WITH IAC OUT OF ITS BORE AND PLUGGED IN!!!!! it will shoot the plunger out and make junk out of it. Also, I would strongly recommend taking your vin # (at least the last 8) to your dealer to ensure you get the proper part #. I seem to recall installing one in a van and getting a p0505 (only had idle problem prior to that) and discovered there are several different part numbers even though they will install and plug in ok. I hope this cures your check engine light! If you need any other assistance, just ask.-Jeff

 

The Dodge dealership is 37 miles from my home. So, I went up today and got a new IAC. The parts guy told me that I cannot clear the P0505 code without having it reset by an OBD scanner. I had left the battery disconnected. I put the new IAC on and the MIL is still on and code is still P0505. So, can you tell me if what he said about clearing the code is true?

 

Not sure if it's true or not that the code will stay in memory, but as you've already witnessed several times, the light goes off on it's own.