Help! Help! The dreaded T/C issue and continuing saga


Please help! I am at wits end. I know this has been covered in some other posts and on different forum but none exactly address where we are with my issue.My 2003 G500 had been spontaneously going into T/C neutral for quite some time. Four weeks ago it did it at a truck stop three hours from home and took an hour before I could get it to engage and drive home. Sooooooo, I took it in and they said Transfer case motor. They switched the transfer case motor and it is mechanically engaging but the little H and L in the instrument cluster is gone and only when you open the driver side door the T/C in neutral flashes and annoying beep occurs. Putting on the hand brake will stop the beeping. We then (based upon previous posts) order ($500) non-returnable T/C module to cure this and have installed but it will not work so the old T/C module goes back in and we still have the problem. We not only had an independent shop with Star diagnostics but the Mercedes Dealer shop try the new module and attempt to solve the problem but to no avail. Someone please help. This problem is driving us crazy and we have not had the car for now going on four weeks. Help! Help!

Recommended books for Overlanding

Yeah, had this issue about a year ago and it was the tcase motor. You may also have another issue going on that it is causing your issues.


Expedition Leader
i would toss this over to P3 or club Gwagon, just to double check the bad new tcase motor idea. i am by no means a 2003 mechanic, and im not saying the poster is wrong, i just have doubts the new motor is bad unless it was boggered somehow on install.

myself, i'd be looking at buss connections under the dash, or a relay. theres gotta be relay somewhere i would think.


Regular guy
After replacement of the TC Motor or Control Unit, the TC needs to be relearned with the help of Mercedes Star Diagnostic system. If those are good parts then that should be all that is needed.
I presume that you have shifted high to low and back again after the install. Often that is enough.