I believe you are saying everything functions correctly except for the top…
when you push the up/down top button, does it blink red?

also, check the valet switch in the glovebox, can be difficult to see…
and, make sure the trunk slide cover is seated properly to engage the microswitch.

you can download or order a free hard copy of your 2002 SC430 owners manual at Lexusowners.com

 

I think you might have to move on to actual convertible diagnostics using Techstream. This will let you know what is keeping your top from opening.

Just google site:Clublexus.com sc430 Techstream to find out what you need to know

 

Since the problem started, no blinking lights when I press the button. When I took it to the Lexus dealer, they told me that they are not reading any codes and if I want to check it they would start with the motor. I have tried the valet button, the trunk cover, I might eventually have to go to Techstream route if the motor swapping doesn't work. Technically speaking, I just disconnected the main switch and replace the glass window. From your perspective, what could trigger the problem? My understanding is that the auto up/down starts the top sequence and if that is malfunction then all you have to do is to reset it. If you can't reset it then it must be the bad motor that can't be reprogrammed. Hopefully, after the motor is replaced and reset it would work. Is there any fuses in there that I can check or replaced that might help solve this problem? Thank you.

 

You can try put the key in the driver side door turn it to the left and hold it the windows should all go down see if that works

 

You are correct saying the auto window must be operated for the top to work. From your description, it’s obvious that what you have done with the window caused this. Go back to see if all your connectors are plugged in securely. Your motor appear to be working since you can low or up your window. It’s just your auto switch or auto function is the problem.

 

The convertible top is unique in the fact it does not leave residual codes in the ECU like most error codes.

In order to get techstream codes, you need to have it running and try to put the top down. That is the only time codes will be displayed.

Most likely the dealer only hooked up and read the error codes stored in the system (Which the convertible top system does not do)

 

I tried the key in driver side door and that didn't work either. I guess I'm going to try to replace the motor to see if it can be reset. I'll check with the Ebay seller first to see if it works properly when they took it out. I've looked at some of them and they do have warrantee. If that doesn't work I can send in the motor to Rockauto. I have a buddy who owns a body shop next to Hendrick Lexus here and he's worked on a bunch of them from the dealer. I will ask him if hecan help out. After that it probably will go to Lexus to get fixed.

 

I have another question. My car is a 2002. If I replace the motor with a used one from Ebay that is from a newer model year, i.e.2005 or later, then it should be much easier to reset the window auto up/down than that of a 2002, correct? From what I understand, with the newer model, you can reset it just by holding the master switch, not having to get to the motor as in the 2002. If you have a newer model year can you tell me how to reset your auto up/down? Thank you so much everyone who has been respionding to my questions.

 

your question would be better answered by Alexis Mechanic or perhaps Lexus parts department as far as I know the Lexus 2002 up to I believe 2006 would most likely have use the same motors you want to open a little down there’s somethings been available for a long time again I don’t know for certain but your questionWould be better answered by Lexus mechanic

 

My biggest fear other than hyperinflation in the US is my convertible top on my 2003 not working one night. So far it’s been a dream and testament to Toyota that a heavy 20 year retractable hard top still works

 

The owners manual explains how to perform a manual closing of the roof in the event there is a problem with the automatic mechanisms. I would suggest that you try doing that during a daylight period just to familiarize yourself with the procedure. Then, if you ever have an issue when you are out on a road trip or when driving at night, you will already have experience on how to use the manual procedure. I previously owned a hardtop Mercedes and did have an issue. I read the manual and found out how to close it manually. The procedure was easier than I had expected. It turned out that the hydraulic fluid had gotten too low due to a leaking cylinder.

 

My top wouldn’t go down, so I checked the fuses and then found the post about the valet switch. Problem solved! I guess I flipped it when going into the glove box while I was repainting my hub covers (the non-pie plate kind).

I’ve owned my SC430 for a dozen years, and if I ever knew about the valet switch, I’ve forgotten about it by now.

One other thing I’ve learned is that the inside trunk release is also disabled when the valet switch is activated, so that should be a clue to what’s happened.

 

Anytime the Close/Open switch is flashing when it’s pushed, that indicates the valet switch is ON and/or the trunk cover is OFF.

 

I have tried pretty much everything suggested here hoping to get my top to work but to no avail. I also replaced the driver side window motor, then replace the driver side door ECU. I still couldn't program the Auto Up/Down function to work. I'm thinking of replacing the master switch on the driver door. Do you think this will help?

 

it looks like you’re just changing parts, hoping that you found the right one. I would definitely go to a dealership and get it diagnosed with their code reader, and this way you could mail it down better than what you’re doing now that’s my advice.