I have a 94' S500 with the ASR problem. It comes on in the morning about 5 minutes into my drive. 6 months ago I decided to throw some of the cheaper parts at it. I installed the brake light switch and the problem went away for the last few months. It now happens again and I have an idle speed switch I have yet to install. Can someone tell me where it is. I have looked around the gas pedel, but can't find it. Any help would be appreciated.

 

on the throttle valve.