C200 1999 115,000 miles - W202 auto. gear change problems - whohellhe

My Merc gear change has been tempremental. 4 speed auto. The gear change sometimes defaults to 2nd and third gear only. When you pull over and restart the car everything works normally. Then 2 days later 2nd and third gear change only again?

Appreciate any assistance in this matter.

Many thanks

J