Mercedes Sprintshift problrm?

I have a Mercedes 316 based motorhome with a sprint shift gearbox. When I start the engine and select "A" auto everything is fine but after 5 or 10 minutes the gearbox goes into manual mode. It drives okay but will not return to auto mode until I stop switch off the engine then restart. Auto mode is selected but again after a few minutes goes into manual mode again. Can anyone throw any light on the problem.
AC, October 2011


done
youll need to get a download, but my guess will be a brake light switch adjustment, or it thinks a door is open

tony friel, November 2011
As it functions OK manually I think you have a control problem. Diagmostic equipment will needed to look at live data and possible codes. Idealy Merc gear as most other diagnostics will not work.

mags, October 2011
link Click here to see other fixes for Mercedes.