2017 Teryx 4 4x4 not working

I have a 2017 Terex 4 and used it last year with out any problems. I put it in storage and it has been there a while. Got it out and had to install new battery. Now when I try to put it in 4x4 it does nothing and the check engine light comes on. I can put it back in 2wd and shut it off and restart it and no check engine light until I try 4x4 again. Any one have an Idea what is wrong? Anyone know how to check why light is on without taking to dealer?