The later 163 ml car's transfer case motor loses synchronization and needs to be reset. I don't think this applies to the earlier cars but you can try it anyway. There is a dtb out about it. Start your car and put on the parking brake. Put your ML in neutral and press the low range switch. Your light will blink 5 times then go out. Now take your foot off the brake and push the switch again. The light should blink 5 times and now stay on indicating that your car is in the low range. This somehow resets/ resynchronizes the transfer case motor position. I believe there is a software fault of some kind, and the motor doesn't know where it's at and loses position. Try this and let me know how you guys make out. I'm pretty sure that this is the procedure, but I'll double check tomorrow at work. Hope this helps.