Toyota: check engine light on with code P0505, toyota supra, idle control system malfunction

Question
My 97 corolla didn't pass the smogg check due to the fault code p0505 idle control system malfunction.  So what specificly is the problem? What do I need to repair or replace so I can pass my next smogg check.  Any ideas?  

Answer
http://www.97supraturbo.com/Trouble%20Codes/P0505%20Idle%20CV.pdf

Follow this link to the PDF file, just read the first page.  towards the middle of that page you'll see the little square that tells you the four things you need to check.  The information after that doesn't apply specifically to you because it's for the Toyota Supra 6 cylinder engine and not your 4A-FE 4 cylinder but the codes and reasons for warning lights to come on are the same because.. above all else.. It's a Toyota:)