UK Auto Repair Questions?
Your transmission is easy for a GM tech, but no dipstick for you to check fluid level.
So "sealed" in regards ***** ***** but not to a technician.
The fluid level is checked at a specific temperature range, so a scan tool needs to be connected at the same time.
The first thing I would do is scan for any codes set, then take a small fluid sample, then top the fluid, and get the level correct, then reevaluate.
Hope this helps.
Do you need any further help?
I hope my advice has been of assistance to you.