Making 2 Keys Into 1 Key

[zalik22]

Hi,

I purchased a 2004 IS300 from a friend that replaced the doors on the Lexus. The master key he gave me lets me use the keyless remote or master key to open the doors, but I have to use the valet key to start the ignition. The valet does not open the doors, but starts the car. Is there a way to unlock (via remote) and start the car with one key? I took it to a Lexus dealership and they said it requires reprogramming/recutting that will cost over $300. I was thinking I buy an uncut shell on EBay, transfer the transponder, and cut it to match the valet key. Would this work or are there some programming/computer issues I would have to take care of? If I have to reprogram, can I reprogram with just the valet key?

Thanks in advance!

[IanH]

To do this yourself you need a Master key that fits the ignition. Go back to your friend and ask for the original master key(s).

(are the transponders in your keys already?)

If you have the original already programed in transponders in your keys then yes get a blank, get it cut and swap transponder / remote unit and you are good to go.

You cannot program a new to the car transponder without a master key. The dealer can do it from your VIN for 2002-on cars, so you are in luck with your 2004, others with a 2001 are screwed and need an ECU.

[zalik22]

To do this yourself you need a Master key that fits the ignition. Go back to your friend and ask for the original master key(s).

(are the transponders in your keys already?)

If you have the original already programed in transponders in your keys then yes get a blank, get it cut and swap transponder / remote unit and you are good to go.

You cannot program a new to the car transponder without a master key. The dealer can do it from your VIN for 2002-on cars, so you are in luck with your 2004, others with a 2001 are screwed and need an ECU.

Thanks for the reply. The valet is just a gray key with no transponder. The master key (black) has a transponder which works, but the key itself is cut different and does not work in the ignition. I was hoping I could get the uncut key with empty shell, have it cut as the same as the valet key, and transfer the transponder from the old master key to the new key. Would this work? I saw some places you need a master key to program, but it seems like I don't have to program anything. Hope I am clear on this.

[1990LS400]

The valet is just a gray key with no transponder.

I'm tending to doubt that. When I bought an extra master key and an extra valet key for my 2000 LS400 back in 2003, the service writer programmed both keys to work in the ignition. If the new valet key didn't have a transponder, I don't think programming it would not have been necessary or even possible.

Whatever you do, you should have more than one fully working master key and you might as well have at least one extra valet key - particularly since they are inexpensive. I've got three full sets for my LS - one for my wife, one for me and one backup set in a secure place.

!Removed! happens. You don't want to be in disaster mode if you ever lose your keys.

[zalik22]

The valet is just a gray key with no transponder.

I'm tending to doubt that. When I bought an extra master key and an extra valet key for my 2000 LS400 back in 2003, the service writer programmed both keys to work in the ignition. If the new valet key didn't have a transponder, I don't think programming it would not have been necessary or even possible.

Whatever you do, you should have more than one fully working master key and you might as well have at least one extra valet key - particularly since they are inexpensive. I've got three full sets for my LS - one for my wife, one for me and one backup set in a secure place.

!Removed! happens. You don't want to be in disaster mode if you ever lose your keys.

Sorry, you are correct. The valet key has a transponder, I guess it's hidden in the gray plastic. Now I am doubting if I can get a new key to work with the shell and uncut key I bought on EBay. My "master" key has a remote that unlocks/locks the door, but the key isn't recognized when it's put in the ignition. Even if I get a key cut that matches the cut on the valet key and switch out the remote portion of the key, I don't think I can sync it with the ignition to actually start the car. Wow, I thought this would be a simple fix, but I guess not.

[zalik22]

Ok, here is an update on my situation. I have a valet key that starts the ignition. I bought a blank shell off Ebay and had it cut to the same cut as the valet key. I switched the transponder from the master key so I can use the remote to unlock the doors. Now my only problem is having the key work so that the engine "recognizes" the master key. Do I have to take this to a dealer or is there a way I can do it? Thanks again.

[1990LS400]

Whoa there. I'm not all that knowledgeable about this stuff but I don't think the purpose of the transponder is so you can unlock the doors. My understanding that it's purpose is to allow starting the engine. Here is a website that explains it: http://www.wisegeek.com/what-are-transponder-keys.htm

[SKperformance]

you need to rekey the cylinder .

It sounds like the door keys and lock cylinders where changed but the ignition left , probably after loosing them somewhere.

You can replace the pins in the tumbler for the ignition and use the key for the doors to start it .

Find a locksmith who can do the service repinning , get the key programmed if needed at the dealer or locksmith for the transponder to start the car .

[zalik22]

Thanks everybody! I got the empty shell off Ebay, switched out the transponder and got it cut for $35. No additional programming was needed. Thanks again!

[cduluk]

So you have a valet key that has the correct blade and starts the car? And you have a master remote that can lock/unlock the car? Then you're good!

There are 3 components to a key:

1. cut blade

2. remote (piece with the buttons) that can unlock/lock/panic the car

3. small "chip" that allows the engine to start.

The valet key has parts 1 and 3. The chip is embedded in the plastic.

The master key has all 3 parts.

Here's a master key. The remote can be removed. Note this is for my Rx400h, but the remote for your car is very similar.

If you take the remote apart, you'll notice the gray/black "chip". This is the part that is programmed to the car to allow the engine to start when near the ignition cylinder.

This chip can be removed from the remote.

What you need to do is destroy your valet key and find the chip burried inside. The chip is VERY "hard", almost like a solid piece of rock, so don't worry about breaking it. Then remove the chip from your master key remote and replace it with the chip from your valet key. Now you'll have a working remote with the chip that's programmed to your car. Then you'll need to buy a new master key shell and have the blade cut to your car based on the pattern from your valet key. Then assemble and enjoy!