This is my first post to the forum after reading for a while.
I have a 2000 ml320 with 67k miles. Recently I've had a problem where the car neutralizes while driving on the highway at about 55-60 mph. I need to slow down to about 25 mph to get the car back into drive. I also encounter a hard 1-2 shift when driving at lower speeds. The problem occurs only once in a while. It occurred today and when I hit the brakes as it neutralized, it felt as though the brakes were locking up. I'm not sure if the two problems are related or not.

The condenser plate was replaced and I was told that the problem was not with the transmission but rather something electrical. I had the battery refilled so that shouldn't be a problem.

I had the car scanned today and a code appearing was that there was a problem with the voltage supply to the transfer case. I was told to check the electronic connections to the transfer case, ABS pump, and then the relays and if that doesn't solve the problem, then the problem could be with the control module.

Has anyone had this sort of problem or can provide any insight as to how to handle this problem?

Thanks!