I used the procedure below to program my new keys to the GS430 but didn't bother with the trunk. Now I would like to get the Trunk release on the key working too and was wondering if we have a programming procedure for the SC as well including the trunk release? Nice to have in my pocket if I ever needed it.

https://www.clublexus.com/forums/gs-...400-430-a.html

Paul

 

hey paul, the trunk is programmed when you program the door lock/unlock module

 

It wasn't on the GS so I guess I need another source for that car or the lock mechanism is bad. Hmmm. thanks.

Paul

 

Paul, is the trunk release not working when you push the button on your key fob?

 

No Sir. And the car doesn't chip when you hit the unlock button which tells me the actual trunk release may be defective. I learned that little tidbit from watching the last episode of The Car Care Nut. The only other really annoying thing going on is you have to be right next to the front door (either side) for the doors to unlock. More than a few feet away and it just can't process the signal it seems. Other than a failing mode selector solenoid, (and a possible crank shaft seal or camshaft seal failure) I have every other bug worked out on the GS430. Next is some interior work and paint.

Paul

 

Something else I just thought to add. The trunk release inside the cabin does work. Just a little FYI.

Paul

 

good to know the trunk opens from the trunk release button.

the C-best settings allow four key fob modes …one of them is off…another push twice…see the document here, item seven.
https://www.clublexus.com/forums/sc4...l#post10604513

the module button for the trunk could be bad.
Techstream or another key fob could be helpful.

 

Yea. About Techstream. I have been meaning to talk to you about that! LOL. But the doors all unlock with two pushes of the button. The ciruit is very simple. So simple, it's hard to see how it can be the trunk release itself since it gets it's signal basically the same way as the SC. It has an ECU that receives a signal from the inside latch. If that ECU signal is working, I may be looking at something else further upstream. Why Lexus had to go and change the names of similar components between models beats me. Anyway. This is a GS problem so i don't want to waste too much of peoples time. i was just wondering if there was a quick answer. I am working with two other people on that forum on basically the same issue. We'll get it sorted. Thanks.

Paul

 

Well. This will come as no surprise to people who have been around here for any length of time. But Bgw70 is right on AGAIN! I had an epiphany earlier today and thought that maybe my trunk unlock wouldn't unlock using my fob for the simple reason that it was too far away from the receiver. So, I went out to the car, stood by the door and pushed the trunk release on the fob and low and behold the trunk latch popped and the lid was open. Thank you for keeping me focused enough to realize that the trunk was indeed programmed. Now my issue is why is the fob range so limited? Cheap key? Or bad transponder key coil maybe? Anyway. Respect Sir! Thanks.

Paul

 

Weak battery!

 

LOL. You know better than that. I just installed new batteries about three weeks ago to see if it was a weak battery. 😁

Paul

 

Paul,

I did an experiment while back and the key fob worked amazingly at the distance of 140 ft.

https://www.clublexus.com/forums/sc4...l#post11030341

 

I believe you. Absolutely. But for this particular car, it only works 2-3 feet away on a good day. I have two remote keys. One key won't open the doors from the outside at all. Starts the car no problem. Unlocks the door manually. So it is talking to the immobilizer. Which makes me think it's not the key coil. But it is by far not a common problem. 🤨

Paul

 

I did the experiment with my SC. I used to have problem with the key fob won’t open the doors even for few feet away, specially in the bright sunlight . I changed the battery and the problem went away.

 

This has never been an issue for us on the SC forum that I am aware of. Like I said previously, this is about my 2003 GS430. But their are are others over there that are experiencing a similar issue.

Since the circuitry is basically the same, (a coil antenna at the ignition switch, and a Transponder Key Amplifier) that is part of the immobilizer circuit, I am still hopeful that I can get this figured out.

The fob battery for one key has been changed twice. The key coil is obviously detecting the key code from both keys because the car starts. But what I haven't checked yet is the RF field of each individual key.

Like I said before, these keys were provided by a third party. IF the keys rf field generated is normal, then I think my options are to change the key coil or the transponder Amplifier. Just laying out my issue. And as always. Thanks for the assist. 😁👍

Paul