RX300 Door Lock Actuators

 Possibly the most irritating problem I've had with the RX300 is the door lock actuators failing.  This is not a problem that is obvious at first.  You have to press the key fob buttons a little more at first, and wonder why.  Then the lock on one door might stick a little.  When you lock the car it may take several attempts to get a locked signal from the car.  Eventually the actuator loses it automatic control, and you are locking doors manually.  Then in cold weather the car may refuse to lock, or unlock.  Ultimately I was having to use the key manually, in the door, which wound up setting off the alarm until I could get the key in the ignition.  These are all symptoms of the door lock actuators failing.  Once you find out that these are $10 parts the stress from the part failing is alleviated temporarily.

 Then you find out that the labor is rated at 3 hours each!  Wut!  The door lock actuators live at the latch of the door.  So they are in one of the least accessible spaces.  To replace four of these door lock actuators you have to disassemble all four doors.  So, the labor makes sense, you have to get through all the trim, and replace the parts that are inside the door.  The first door did take a full three hours, but each successive door went quicker with experience.

 The door lock actuator itself, bone colored piece above left, is part of the latch assembly.  This is the latch mechanism for the door, and it connects to both the exterior handle, and the interior handle.  Once you get the latch assembly removed then there is a little more disassembly to get to the door lock actuator.

 You can see it a little better in the picture above.  These actuators are servo mechanisms which have a motor, and a gear set that do the lock, and unlock functions.  The motor drives one way to lock the door, and the other way to unlock the door.  This module is separate from the door latch, and door handle interface functions.  The door lock actuators also provide feedback to the computer for the status of the lock.  These $10 parts are the sensors for the security function.  If the car has trouble locking a door, and the door is not in a locked status, then the lock the car function will not return the car locked status beep when you press the lock button on the key fob.  These modules are an important part of your security system.