Most of the time the rear driver's side door stays locked even when key fob or button is pushed to open. Occasionally it will actuate with the rest of the power door locks and almost always lock but not open. Any thoughts on this one would be appreciated.

 

A couple of things come to mind.................

1. The vehicle settings in the BCM may need to be rest. By that I mean to go back and review your settings that you have currently by searching those settings using your steering wheel controls. Make sure that the settings are where you want them to be.

2. Your remote key fob battery may be weak and not sending a strong signal to the vehicle.

3. (less likely) The locking mechanism in the door is old and needs replacing.

Start with these and see what happens.

 

Mine does the same thing. I can see the lock tab twitching, but it doesn't unlock fully.
Ive been meaning to investigate it more. Just been busy.