I had the car serviced for a bunch of things by a MB Dealer and they said that the 4matic problem I had was related to the bad battery I had and that there was nothing wrong with the 4matic system. Now about a month later the light is back on and $WD is off. Is there anything obvious I should check or a decent refernce book on the 4matic? I tried the MB CD Rom but it had no information at all.