2015 Prostar wont go past 5th gear fault code 71

Truck has run fine until it wouldn't go into reverse. My alternator voltage was down. I replaced batteries. Not sure if I connected batteries correctly. Not negative to positive. I've heard before that the first battery should some how be connected by itself or some along those lines. I've read through the other threads regarding this issue. I paid a service truck to come out yesterday but I know more about this truck than he does. So I'm still broke down at the truck stop diagnosing the problem myself. Could it be low on fluid or need clutch adjustment. Some please help.
@Heavyd, can you help?

 

It only shows code 71 and 27. No more codes. Thanks for reply

 

I changed range sensor. Still only goes to 5th gear. Codes are below. Thanks.

 

I changed range solenoid and still 5th gear only.