Sounds like it could be the top ECU [ Located in the trunk under the floor boards ] The top must be connected to the windows in some way because it does control the rear windows in a sequence when your putting top up or down,

 

That sounds to be right. I'm just stumped on this one. One would think if there's no light on the button when pressed it might be a fuse. Do you think if the ecu is bad it wouldn't send any signal anywhere even to the button to lite up? Would autozone be able to run a reading on the ecu see if any code pops up?

 

The codes you need are proprietary to lexus I dont think autozone could read. You may have to bite the worm and go to the dealer . The diagnosis would be very helpful to you if you want to DIY if its part swap
Might be worth spending the money for the diagnosis

 

And the top up/down switch will control the main windows up and down.

 

I m trying to get another top ecu and see if that's the problem

 

What year is you sc430

 

2002 (10 character)

 

I've seen the button light off when the top was not functional also but never discovered what the problem was. (My problem is intermittent.) However, if your problem is related to the windows, you might check out the window ECU inside the driver's door. Maybe the connector has a bad connection that the roof ECU checks. (It is possible that one of the pins in the connector has backed out slightly.) Then again, it could be on the roof ECU side.

 

I really don't know if the problem is related to the window or not, the top stop working the same day the auto window up/down stops working. I will take a look at the window ecu. Thanks

 

Keeping this thread alive, I have ordered another top ecu and I should recieve it in a couple of days. I will post if the ecu work or not. I've ran a cross an older post from another member in the forum who had the same exact problem, he said that his top ecu was bad therefore his button would not light up or have any function plus his auto up/down window was not working. Fingers crossed that it's the ecu and a easy fix. Weather here in Texas is getting better to go topless.

 

Definitely keep us updated and let us know any "pro tips" you learn from the install. Pix always welcome.

 

My top ecu came in today and just installed the ecu. Everything works, auto window up/down and top works like a charm. To top it off it only cost me 150 bux. I'm a very happy guy, just in time for the nice weather.

 

Did you take any pictures of the replacement?

 

Are you talking about a diy or the replacement top ecu?

 

A DIY would be awesome but short of that I was hoping that you got pictures of what was replaced and where it is located.