2010 tahoe, 111k miles. Has been running great and have had no issues. Had this truck 11 years now. Getting off work today, went to start it and check engine light came on. Didn't think much of it, was going to check it out once I get home. As I switch it to drive the truck seems to be stuck in first gear, would not shift into second. Even tried manual mode and its not letting me shift. Seems to be electrical since transmission has been shifting smoothly, haven't had any issues. Battery is roughly 2-3 years old. Hooked up my scanner and got P0700, P2534. Please help.