I have a 2003 GS 430 with an intermitent remote door lock problem. At times the remote feature will not work at all. I have noticed that the problem seems to originate when the car is placed in gear and the doors are supposed to lock themselves at some point. When this works normally I will have no problem locking the doors remotely when I leave the vehicle. Sometimes, however, the driver's side door manual lock does not rotate to the fully locked position. When this happens, I cannot remotely lock any of the doors - there is no beep or any indication of a remote function. To alleviate the problem, I have taken to cycling the manual door lock on the driver's side door after departing in the car. I believe that someone's suggestion that this may be do to a weak spring in the door locking mechanism is consistent with what I have observed. I do not know if replacing the spring independently from the door lock mechanism is possible.