1998 Ls Key Programming To Start The Car

[itarumaa]

I have 1998 LS400 and I bought a new key from eBay.

Now when I tried to program the key to the car, wireless part was no problem but actually to be able to start the car with the new key, no luck.

I followed instructions from service manual but still nothing.

When I enter to to the programming mode, the security light blinks once and after that nothing. Even I wait for 2-3 minutes, the key does not get programmed but also the security light does not blink more than once. If I stop the programming sequence, then when entering the new key to the ignition, security light blinks and if I enter the master key, security light stops blinking.

But what is so strange here is that the new keys opens the doors without any errors.

Does anyone know why in programming mode the light only blinks once, since it is supposed to be doing blinking all the time untill key is programmed.

[Ruud]

If you have bought a complete (strange) key, the ECU will have to be programmed to accept the chip in the new key to disengage the immobiliser. Which is a different procedure.

I could be wrong, if so, someone else will come to tell me off :)

[cruisermark]

Hi

Fieat of all make sure you get the correct key - it should be a denso 12569 and the lock button should have a dot on it and the unlock button should have a triangle on it

The method i used is posted here by haylands here and it worked fine:

http://www.lexusownersclub.co.uk/forum/topic/47560-ls400-key-programme/

[itarumaa]

My master key has dot in lock button, but no triangle in unlock button, same with the new key.

Both are 3 button keys. I think I will change the Battery to master key and try again. I have tried both method 1 & 2 from the link cruisemark posted.

I think this is the method to program the key to the ecu.

[The-Acre]

I went through this earlier in the year and struggled at first, but managed it after about 10 attempts. I did make sure the spare key was identical to the master, i.e. with the triangle and the dot. In the end I wrote out the instructions so they were easier for me to understand. If you pm me your email address I'll send it to you as it may help.

[itarumaa]

Ok, so I went to the local locksmith and they said that the keys do not match with the master key and secondary key.

They were able to order me a new key, it will not have a remote function but it should start the car.

So then I can use the another key to open the doors and another to start the car, good enouh to me :)

And will also have existing master key as a back up.

[The-Acre]

I thought the key that goes into the ignition had to be programed or the immobiliser will prevent it starting, When I had mine cut, it would turn the engine over, but wouldn't start until it was programed.

[itarumaa]

There are actually two different items in the key integrated under a plastic cover (chip). First one gives the signal to the car to open and close the doors, but second one gives the signal to the immobiliser to actually start the car. And now the second chip does not match with the master key. Therefore I can program the key to open the doors but I cannot program the another chip to start the car.

[cruisermark]

Ok, so I went to the local locksmith and they said that the keys do not match with the master key and secondary key.

They were able to order me a new key, it will not have a remote function but it should start the car.

So then I can use the another key to open the doors and another to start the car, good enouh to me :)

And will also have existing master key as a back up.

that doesnt sound right - the remote key has the gizmos stored in it - and when inserted will start the engine - if the new key is plain non remote key how will it start the engine?

[itarumaa]

Great news,

the local locksmith was able to create a new key to my car and even better is that it works.

It does start the car and I can open and lock the door manually without triggering the alarm.

So now I can use the key from eBay as wireless function and the new key to start the car and master key I can leave as spare key.