All of a sudden the rear right passenger window doesn't stay closed, it goes all the way up and then it goes down half way. It doesn't matter which switch I use, the driver's side or the passenger side. All the other windows go up as soon as you toggle the switch automatically up and stay up. Have anyone experienced this kind of problem with their GX? I made an appointment to take it to the dealer on Saturday, it sounds to me like bad sensor?

 

The part about going down only half way might be a clue. What is supposed to happen when we close a rear window and it encounters an obstacle, e.g., a child's hand or a dog's neck? Obviously, it should reverse the motor and open the window, but all the way or only half way? If half way then the problem could be an overly sensitive obstacle sensor, which is falsely triggering.
Regards,

SaniDel

P.S. You could test this by putting an obstacle in the way of the other rear window, closing it and seeing what happens.

 

I'm fairly certain it is the "Jam Protection" function falsely triggering. I've appended a quote from the manual that describes what is supposed to happen, which seems to describe your problem. Your dealer should be able to deal with this, but it may mean getting inside the door to get to the sensor.
Regards,

SaniDel

 

If the window is dirty it can cause some resistance in the window chanel or seal. Clean the window inside on the and on the outside and try it again. Also check the rubber seals if there is any dirt or small items in the track. My drivers window sometimes rolls back down when dirty.

 

After dropping the GX at the local dealer, they found that the motor was the culprit and replaced it. Was really nice about this trip was that while the truck was in for the window I supposed they did a complete diagnosis of the vehicle and found that the rear differential gasket was leaking so they went ahead and replaced it and refilled the differential with fluid. I normally look around for signs or issues and this time they did the detective work. All was covered by the warranty so I was a happy camper. I wonder if all the Lexus dealers do this kind of engine and body diagnosis.