2002 q45 p0505 iac code

[xrjoe]

I have this code still, after running the iac re-learn procedure, lite wont go out, I did clean throttle body with spray, also on a very intermittent note, ive seen a p1135, that has not returned, I need some guidance to repair the iac code. please help.

[xrjoe]

nobody has experience with this? with no solenoid to replace(iac), im guessing the whole t-body gets swapped?

[xrjoe]

well I cleared and ran the relearn 10 more times, the rpm seems to be responsible for setting the code, 6-700 is spec, im 950, if I pinch the pcv it drops to 850, not sure if that's enough to satisfy pcm....

[xrjoe]

with restriction in pcv to lower idle, in drive stopped im running 650 rpm, in park still 850, im thinking still too high. it takes 30 plus miles to set p0505, and unfortunately it still comes up, still need help.....

[Q451990]

Sorry we left you here talking to yourself... to NICO!

So when you cleaned the throttle body, did you manually open the plate? Have you read the factory service manual regarding the code? http://www.infinitiservicemanual.com

If it's like my wife's G there are two relearn procedures that have to be done in sequence. One for closed position, and one for idle air volume learning I think?

Heath

[94Q45Beast]

Q451990: can you go into a little bit more detail about how the idle is affected by manually opening the throttle plates? as you already know, I do have idle problems, probably the thermostat?, most of the time when I start the car it idles at 600rpm - 650rpm in P and N gears and 500rpm - 550rpm in reverse and all drive gears. and occasionally when I start the car it idles in park and neutral at 1400rpm and in reverse or drive gear it drops to 950-1000rpm and then goes back down to 500-500 rpm after I hit the freeway, oh and I went ahead and guessed on how much I need for the paint, I'm doing a tri coat. will upload pics when I'm done.

oh and I'm so so so sorry for trolling on this post, I sincerely do apologize.

[Q451990]

Q451990: can you go into a little bit more detail about how the idle is affected by manually opening the throttle plates?

Don't worry about trolling a post - that's never been a big deal here.

The 2002+ Q has what's called a drive-by-wire throttle system. That means there's no throttle cable connecting the gas pedal and throttle body. Instead it uses a variable resistor on the pedal, and a servo mounted to the side of the throttle body to open and close the throttle plate. The cool part about this is that there's no need for an IAC valve, because the ECU just adjusts the throttle plate as it needs to. Simplifies cruise control too.

Anyway, forcing open one of these newer throttle body plates can damage the servo, or whatever sensors they're using in there to monitor the plate's position - and the relearn procedure fails.

The older cable fed throttle bodies are fine to open and close manually.

[94Q45Beast]

ok thanks for clearing that up for me, and any thoughts on the symptoms I described?