The transmission drive selector module may fail resulting in the loss of gear selection capability. This condition can leave the vehicle stranded, and will require replacement of the drive selector module.Google+
Car Problem Reports
Mercedes-Benz ML320 CDI The Transmission Drive Selector Module May Fail
Mercedes-Benz ML320 CDI Problem
Visitor, 2007 Mercedes-Benz ML320 CDI
gear stuck in park. light on dash that indicates which gear it is in doesn't illuminate. Is in "limp" mode when you override the selector;
Visitor, 2007 Mercedes-Benz ML320 CDI, 89,000 mi
Transmission won't shift from neutral after it starts to go it stops and revs engine up leaving you stranded in the intersection to be hit by oncoming cars.