I have a 99' Oldsmobile Aurora and the passenger side front door does not unlock. I have had trouble with it before but it seemed to work itself out and work again. When you hit the unlock button the lock mechanism moves a little bit but does not move enough to appear unlocked. You cannot manually unlock the door either to allow for it to unlock. The outside lock mechanism appears to move far enough when using a key to appear as though the mechanism should unlock the door, but it does not. This has happened twice and both times the door eventually unlocks itself and all I manage to do is allow for the door mechanism to move somewhat when you put the car in and out of gear. Is there a solenoid that actuates the door mechanism movement and this is not working properly? Please help.
I would take the door panel off and see if there is any obstruction stopping the door lock mechanism form working. If all of the lock mechanism parts and or linkage check out OK then check the electric door lock actuator.
When the electric door lock actuator gets old it will get week in most cases and it doesn't have enough force to move the door lock linkage.
Replacing the door lock actuator in most cases fixes the problem.