I do not know if this thread is still active, however I have a similar problem with my 2007 Lexus IS 350 ( I just bought it used from a local dealership in Springfield Virginia in June of 2011 and now out of 30 day warranty ). My Door locks work fine except for the passenger front door will not lock or un-lock with the switch on the door itself. The driver side switch will work and the remote key will also work the locks fine, however the passenger door switch itself will not. I just had window tint put on and thought that the installer screwed something up and when I went back in to have them look at it, this is what we found when he pulled the door panel off along with the switch assembly on the door handle. The installer (who was very nice to do this for me) disconnected the locking switch (along with the assembly) and there are two screws holding the circuit board underneath the switch itself. This circuit board pulls away from the switch and has a wire connector on the bottom that goes to the wire harness to the door lock actuator. Now looking at the circuit board when it is installed in the assemble it looks fine, however turning over the circuit board there was a crack all along the other side the length of the silicone board. We could also see that someone attempted to solder two sections of the circuit board (I guess to make the electrical connection for the switch when it is used to lock or unlock the door. At this time I do not know what this part is called or even if you can just order this part and replace the circuit board with the wire connector on it or if I will have to buy an all new switch with circuit board to replace this unit. If anyone can supply a diagram or information in what this would be called or part number etc etc I would greatly appreciate it. I am writing this so that some who might just have one door lock on the car not working (not the driver side as I think that is controlled in a different way from what I have been reading.) might check this small circuit board for cracks or damage. I am going to see if I can use a circuit board from one of the rear switches just to see if this works to let me know if it is the circuit board. I will post once I can find the time to do this.