Why after car warms up and cut it back off.
.when I start it again won't go past second gear any suggestions?

 

Need more info - fluid level correct; fluid color/burned smell; mileage, miles since fluid/ filter change; hard shifting; tried manually shifting or just in Drive; any pending codes; 1st/2nd change normal; then rpm just goes up with no change?

I don't know much about these transmissions but I want to say there is a solenoid that engages 3rd/4th.