Volvo: volvo1995 850wagon, no turbo

Question
Recently acquired the above and the up arrow came on and was blinking. Found after the second day that when driving in "drive" after a mile or so seemed it slipped out of gear, ie engine revving but not moving. After switching off and restarting will go for another mile or so, then repeat. After stopping will not want to go in reverse, only forward. Seems to favor driving in 3rd, but will still not maintain. How do you know when the Winter mode is selected?? Hear it can get stuck in that and not sure how to unstick it. I have run the gear stick up and down through the gears 40 times, to no effect. Hope to goodness the tranny will be fixable for a reasonable amount, should it be the problem. Thanks, Susan.

Answer
Well ,the first thing to do is have the codes checked .Possibily a pnp switch but you wont no until you check to see what is stored in the trans control unit .From experience this trans does not get rebuilt right outside the factory ,so i would opt for a used one to keep the cost down .LKQ sell parts for these cars with a warranty and if needed would be the cheapest way out .A factory rebuild unit runs 3-4k plus installation and would only make sense if the 850 was in great shape. So i guess firstly have the codes read and go from there ...