I have searched the archives here and elsewhere and think I have a new ASC issue.
I recently bought a 1999 528 with 78k mi. I also have a 98 528 with 188k. The ASC on the 99 did not work (couldn't get out of my snowy driveway recently), but the dash light was not illuminated and the ASC switch had no impact.
On my 98 while driving, the light will flicker when I hit a patch of ice and the ASC automatical modulates the speed until traction is re-gained. The dash switch will disengage the system and turn on the light as it should.
I took the 99 to the local indy to get scanned and they said it was the ABS module. I had it re-built by BBA disconnected the battery and re-installed, but the ASC still did not function, nor did the light work. I brought it back to the indy who re-scanned and initialized the steering angle sensor. I picked it up and the ASC does seem to function, but the dash light still does not work and the switch doesn't seem to affect it. The indy suggested the switch was bad, but didn't have any codes to support his diagnosis. It was 5:30 pm and I didn't want to belabor the point so I have been driving it since. The lack of a working ASC light still bothers me though, since I was used to how it functioned in the 98 and it gave a little piece of mind when driving through the many snowstorms here in Maine. Has anybody dealt with this issue ? Suggestions ?.

Thanks !