even if the asc is working, it's only there as a means to correct minor mistakes or incidents of traction loss. not prevent it.
you can still spin out even with a fully functioning asc. do as gtc says, and take your car to a parking lot (empty) next time it rains, or even when you have the free minute to do it. thats about the only way to test for sure.
should it work proporly, the light will come on and you will feel and hear the power cut from the car as the asc tries to controll your acceleration.
<img src='http://www.bmw-forums.com/forum/uploads/post-46-1095116979.jpg' border='0' alt='user posted image' />
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