Jim Grant's Tech Tips
Lexus RX300, Whacked Out Window Controls
Q: When I put down my front driver side window, the rear passenger side goes down. I turned on the car just now & the rear window opened, It is now stuck open. How do I get the inside door panels off? Do you think it's just the switch? My car is a Lexus RX300.
A: First I would suggest checking the fuses, youll find one for each of the power windows and for the computers that control the power windows. If you find the fuses to be good you may want to find yourself a network specialist. The great thing about the higher end vehicles is the technology that is running loose. The not so great thing is when this technology wigs outs and creates bizarre behaviors such as the problems youre having now. There is a computer for each door of your vehicle to operate the power windows. Each of these computers are networked to each other and to the body computer. The window switches at the doors just send signals to the computer. Based on the information the drivers door computer receives it will operate the drivers window, or if a signal is sent to open or close another window the drivers window computer sends that information out on the network. The door computer that recognizes the information will in turn respond and operate the power window it commands. If youre lucky, you have a bad switch and more often than not it is the drivers side switch. All you have to do is spill a little water, coffee, etc., on the switch, and it will work its way into the electronics of the switch and whacko goes the information to the computer. If you manage to get the passenger side window up go to the fuse box and pull the fuse for that window. Without the fuse the computer can command all day but there will be no power to operate the power window. Because the door computers are networked to the body computer a computer scan tool with the appropriate software can be used to check the power windows computers. The technician can check for computer fault codes and monitor commands and responses to diagnose the problem. If you want to remove the door panel and put the window up yourself, it is a bit of work. Once the panel is off you have to disconnect the power window motor from the computer and power up the motor with jumper leads.