Hey Everyone!

I was driving into work, stopped at an intersection with the clutch fully depressed when my engine died. I was able to start it right away but the CEL was on.

Autozone said it was a P1504, and the display said something about "Idle Speed Control", but a Google search also showed "Intake Air Sys.Bypass Leak Detected".

This is a 1997 A4 V6 (12v).

Any clues on where to start? Engine seems to be running fine, no strange noises, smells or smoke. It has been really cold though. They reset the CEL at Autozone and it didn't come on when I drove home.

Thanks in advance

gonzo

 

Could be a leak around the throttle body.

 

I would bet it is actually the idle control valve. Or like Jest says a leak somewhere along the air intake between
the MAF and throttle body, including the IAC valve at the throttle body.

17912 - Intake Air System: Leak Detected

 

Yeah the IAC valves on the 12V engine are known to be problematic.

 

i still get that code everyone and a while and yes my car likes to stall evey one and a while too. i have had 3 diff air intakes ( stock, stockw/ k&n, and cone) 3 mafs (stock 97 stock 96 and bored 97) and 3 tb (stock ,stage 1, stage 3). damn just realized too much work done on intake system. during most of these stages and with different combo's i have gotten this code and i am currently under a cell right now with this prob being the culprit. no need to worry it is just annoying. i am to lazy to vag my car

 

hb972.8q, you have a 12v right?

 

Thanks for all the feedback! I'll stick my nose under the hood this weekend and see if I can track down anything that looks unusual. I've never done any work under the Audi hood, but there's no time like now, right?

I'll google for some repair manuals or diagrams so that I can identify the "idle control valve" and the area "along the air intake between the MAF and throttle body, including the IAC valve at the throttle body". I'll post any interesting findings here.

By the way, I've seen the Vag-Com style cables from China on Ebay for $50. Are those knock-offs worthwhile or do I need to spend more to get the real thing?

gonzo

 

I have a generic cable from obdtool.com. I would recommend buying from ross-tech though. You are still goign to have to register the software with them if you want full functionality.

 

yeah I have the ross-tech USB-Key cable and software.
Its the best software out there right now for us.