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I was temped to find out, but then I found a US spec one for a reasonable price. A vendor I contacted did not know. So, find a vendor that accepts returns, and find out. Then let us know. The control buttons on the top for the sat. nav are different and some are for features that we don't have.
Below are the pin outs for the HVAC controller.
For anyone thinking that it would be nice to bypass the brain and hard wire a DPDT switch to control the hardtop functions, I tried. I blew a fuse. When I installed the replacement HVAC controller and found and replaced the fuse, everything worked.
Talked to a tech at Lexus of Chattanooga. My advice. Don't step for in there unless you wanna be ripped off. First I had an open recall. Which I think they fixed. I asked if they could get a code why my roof wouldn't work. I told them I had a OBD2 reader but they said that it wouldn't be able to get the code for that. They said no no no they had some diagnostic tool that would be able to tell them exactly what was wrong. So my dumb *** agreed to a $200 diagnostic charge believing they would be able to give me some answers. So they have my car for 2 days. When I went to pick it up today they said the top wasn't fixed and it might be the switch or it might be the computer in the trunk they weren't sure. I asked him did you hook it up to the diagnostic tool you were talking about. And most of my surprised the rep said yes we hooked it up to the OBD2 and found no codes. So I'm out 200 bucks still don't know what's wrong except for the fact that the switch is good when I get home I tested it. When the disengage trunk button is pushed I get a red light but no roof movement. When the Trunk disengage button is engaged I push the button getting the red light at the top of the switch. I dismantled The climate control unit and found there was no issue with the switch so my next move which I have done is to buy a sliding roof computer that's in the trunk hopefully that helps. Again if you can avoid it don't use Lexus of Chattanooga because they lie they have no other diagnostic tool that goes deeper than your standard OBD2. I've been a fool. And still I have a manual convertible.
Last edited by Vanmax1313; May 21, 2025 at 06:55 PM.
I was temped to find out, but then I found a US spec one for a reasonable price. A vendor I contacted did not know. So, find a vendor that accepts returns, and find out. Then let us know. The control buttons on the top for the sat. nav are different and some are for features that we don't have.
Below are the pin outs for the HVAC controller.
For anyone thinking that it would be nice to bypass the brain and hard wire a DPDT switch to control the hardtop functions, I tried. I blew a fuse. When I installed the replacement HVAC controller and found and replaced the fuse, everything worked.
Hey Greg
Please share the name and contact info of the vendor you found. Thanks
When I went to pick it up today they said the top wasn't fixed and it might be the switch or it might be the computer in the trunk they weren't sure. I asked him did you hook it up to the diagnostic tool you were talking about. And most of my surprised the rep said yes we hooked it up to the OBD2 and found no codes.
The reason there were no codes is because the Convertible System doesn't store codes. They need to hook up their computer and press the open button to get roof codes.
This is different than other toyota systems.
If you think it is worth your effort, explain this to them and ask them to check for codes again.
The reason there were no codes is because the Convertible System doesn't store codes. They need to hook up their computer and press the open button to get roof codes.
This is different than other toyota systems.
If you think it is worth your effort, explain this to them and ask them to check for codes again.
I've been reading in the forum somebody mentioned techstream. Is this what you're referring to? And if so would only Lexus or Toyota dealer have it or is this a common thing and mechanic shops? What I can understand is why wouldn't they just know this?
I've been reading in the forum somebody mentioned techstream. Is this what you're referring to? And if so would only Lexus or Toyota dealer have it or is this a common thing and mechanic shops? What I can understand is why wouldn't they just know this?
SC 430 is a twenty-five year old automobile. The roof close-open mechanism is a unique design. Not all Toyota-Lexus dealers have knowledge about it. Like DD said, TechStream doesn't store roof fauty codes. So, in order to get the ITC codes, TechStream must be hooked up while the roof open/close command in operation.
Where do you live? If you're lucky, may be a member of this forum who lives nearby and have TechStream can help. Other option is buying TechStream from Ebay, installing to the laptop then hook up yourself.
Roof failures are sometimes simple and easy to fix if you know what was wrong.
I totally understand that. I just purchased a VX DIAG nano for Toyota and downloaded the software from their site it looks like it's techstream 18 but I live in the Chattanooga area so if anybody on here is from around me I would greatly appreciate the advice and help
Last edited by Vanmax1313; May 25, 2025 at 10:34 AM.
What is going on with your top? Is it not opening at all? It is most likely not just the control switch. In fact it is VERY UNLIKELY it is the control switch.
Drive fast over a speed bump and see if that gets the roof to open temporarily
There are videos on Youtube that can help you get techstream installed, or there are many people here that can help you if you have questions
I watched all the videos. I have changed the computer in the trunk. Hopefully I found somebody with the climate control with a working switch. Waiting for relply I bought the vxdiag tool to check codes. It'll be here Wednesday. Haven't tried the speed bump thing tho. When I took it to the dealer they said either switch or ECU. The plastic switch pulls out about a half inch so I took it apart and it just pushes on 2 rubber buttons. So yes I didn't think it was the switch. So maybe the code reader will tell me something.
Last edited by Vanmax1313; May 25, 2025 at 10:29 AM.
We really need the codes to move forward. The speed bump thing is based on the fact that the roof system has a bunch of micro switches in it. If they are misaligned your top won't open. Or possibly one of your roof motors is sticking. Hitting a speed bump fast will hopefully jar everything back in place and your roof will work again.
Once we get the codes, we can work on a long term fix
Soarer climate control unit
