Hey, jbar24!!!!

I was having similar limp mode issues with my '02 ML320. Mia 73 is offering good advice and a good place to start. There are multiple problems that can cause this issue.

Most of the people that I asked for help advised to replace the conductor plate, which I did, but the limp mode issue remained. Next, there was a code for the traction control module. I ordered a used one from eBay and sure enough, that was the issue causing limp mode.

Scan your ML and see what codes pop up. If there is a code for the Traction Control Module, then I would say start there. Regardless... one day you'll want to replace the conductor plate. That's been the only flaw in that transmission.