Logan, Lesson Number One:
When you buy a GM product, immediately order the Helm manual for it. When you
get the manual, sit down, prop up your feet, and read the damned thing cover to
cover for about 2-3 days.
Then when or if something acts up, you've got nearly all of the information you
need for trouble isolation and maybe DIY repair. If the manual makes it sound
like a messy job, then you can take it to a good shop. Several times I have
made a correct and difficult trouble diagnosis and then took it to the shop for
them to do the work. When or if they try to diverge from the isolation
procedure in the Helm manual, then I tell them I will take the car and they are
off the job.