I’ve got an 08 tahoe z71 that I recently purchased from a friend of mine and he stated that he had problems with the electronic locks and had them replaced. There is currently only one door that has a functional electronic lock. You can hear the mechanism on the rest of them but the lock doesn’t move. Any ideas on fixes? My drivers side door is also weird about closing. I cannot slam the door and it remain shut. Any info is much appreciated.

 

If mine, I'd pull off the door panels and take a look-see; might just need some lubrication, like aerosol silicone lube. That's how I fixed one way back, on our 1988 Suburban....

 

All the newer GM door latches are problematic. Most likely the replacements were junky Dorman ones. Put in a GM one and be done. Aftermarket ones are cheaper, but you get what you pay for.
Not locking or unlocking is a common issue.