Try this....(1) Open all the doors. (2) Using your remote, lock all the doors with one press of the lock button. (3) Close all of the doors. (4) Double tap the unlock button on the remote to unlock all of the doors. (5) Lock all of the doors using the remote. The doors should all unlock and lock correctly from now on. This worked for me when the LR door didn't always lock. When I would open that door to lock it manually, the alarm siren would go off. I never did find out why that one door wouldn't lock with all the others but this method worked. I don't know why this worked either !! I wouldn't suspect any of the actuators as they obviously work.