davidavidd
Member
It appears that the truck is in protected mode, if so this sequence of steps may help you.
what do you need? > cell phone's stopwatch app and a charger to keep your Tahoe's battery alive during the process. Follow the steps in exact order, if you fail in just one, start over.
On page 4 you can identify which system your truck has based on the key, I hope this helps, sorry for my broken English, it's not my native language.