This is a very common problem with the ML.. Its your switches that are defective.. I've already replaced it on 4 ML's at my shop.. The problem is you don't just replace one switch like your japanese cars, you have to replace the entire switch assembly.. its actually very easy to do.. just remove everything from the gear shift knob, gear shift cover, coin tray, glove box, cigarette tray, than the wood panel is just clipped on.. and its pretty straight forward after that! just replace your switch with a new one.. and your ML is as good as new..