[drover]

WG's never came with a dip stick..

Oil type may cause problems but just starting up overfull won't other than blowing out breather, too low will foam up and miss or stick changes....
Have a look at the right front of your gear box, there is a large electrical connector, unplug and have a look inside , if there's oil there, thats your problem, new plug is cheap and easy to replace but care is needed as it screws into a very expensive circuit board inside the gearbox... replace plug is available form Benz, cheaper and easier than any dealer.... I always used Penrite in my W5A580 tranny.... as well as in my 8HP70 now.

Otherwise disconnect battery and unplug the TCM and other magic boxes sometimes it works whether fully clearing memory or by ensuring better contacts I don't know.