The on-board programming should be the:
insert key, on, off 5 times,
open door, and close 6 times,
remove master, and sec. light should stay off,
insert new key, and wait till light comes back on....you're programmed.

Unfortunately, I can't get mine into programming mode. When I remove the master, the sec light comes right back on. I've tried the key and door timing fast, slow, even brought out a metronone(sp?) from the daughters piano to see if I could instill consistancy. Nope.

Following is some interesting imput from Tami at Franks Locksmithing who has posted many times in the past . She seems to have a vast knowledge of Lexus and would be my choice for help in the future if I lived closer.

"The 2nd set of programming instructions is for your vehicle (see above). We need to talk about timing. Lexus can be very finicky when it comes to programming. If you don’t do it just right it won’t go into programming mode. The biggest error I usually see is the timing is wrong. How long would you estimate it takes you to go through these programming steps?

(I tried various from frantic fast, to really slow and deliberate).

I want you to watch the security light. Tell me if the security light goes on once you remove the master key and you insert the key you want to program. The light should be off until you insert the non programmed key. If the light goes on as soon as you remove the master key that tells me it didn’t go into programming mode.

Here is another thing. It seems like the SC430 is one of the most difficult cars to program keys into. I’ve heard rumors (nothing anyone can prove or at least I haven’t seen the proof) of Lexus dealerships using the scan tools to turn off the ability to add keys in yourself manually thus forcing the vehicle owners back to the dealerships. I’ve only heard this to be true on the LS430 and SC430. Take that for what it is worth.

I use my scan tool to add in these keys because of the difficulty manually programming in the keys. I don’t know how much this is going to help you but it is the only thing I can do without being at the vehicle."

Sincerely,

Tami

Frank's Locksmith

 

damn JJ sorry to hear. I would not put it past them to do that.

 

man it must be hard to program. i did the programming on my gs400 and it was pretty straight forward (the instructions you posted). good luck

 

I cant believe you have to go thru all of that to program a key. Maybe there should be a sc430 two-step contest at the next meet.

 

I've recently programmed a new transponder/key to my SC430, in the instructions that I was sent, there is a max number of keys it will hold in its memory, (i think it was 5), if it reaches that limit, you have to delete those from the sysem. I'm trying to find the information, once I find it, I'll post some more info

 

I haven't seen anything to delete the 02+ cars. It all pertains to the older lexus.

 

according to the info I got when I purchased a transponder/key
I HAVE NOT TRY THIS,
but I have followed their directions on programming the transponder for my 2002 sc430


to delete all keys except YOUR KEY (the one that is working)

1. have all windows up and doors closed
2. stand outside the vehicle
3. from outside the vehicle, lock the car doors with YOUR KEY
4. from outside the vehicle, unlock the car door with YOUR KEY
5. enter the vehical and close the door
6. start the engine, then turn the engine off and remove key.
7. insert YOUR KEY in the ignition (DO NOT TURN)
8. within 15 seconds : depress and release the accelerator pedal 6 times
9. within 20 seconds : forecefully depress and release the brake pedal 7 times (the security ligh will flash)
10. within 10 seconds : remove YOUR KEY, all keys except YOUR KEY should be deleted from the vehicles computer memory.

 

$78 later, all is well again.
They said that the only way was the scan tool as they "thought" mine was disabled for On-Board programming.
Done.
-J

 

man this is definitely complicated enough....

at least you got your keys programmed