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 R320 CDI The Transmission Drive Selector Module May Fail
Mercedes-Benz R320 CDI Problem
Average Mileage: 111,850 mi (101,000 mi - 122,700 mi)
My 2007 R320 CDI has the same problem. When I went to start the vehicle it flashed a service message that stated I must shift the vehicle into park. The problem is that you cannot start the vehicle in this state. You therefore have no power steering and no means of shifting the gears so that the vehicle can be safely towed. Watching my R320 being towed in this state was like watching sausage being made. I will be shocked if I dont have more damage from the tow than from the initial mechanical failure. This is a huge failure on MB's part not to have a safe means of shifting the vehicle into neutral if and when the gear selector fails.
won't shift from 2 to 3 upward nor 4 to 3 downward....but can do it manually with the finger paddles behind the steering wheel.