eld4au6

Hi, I'm new to lexus's but a long term toyota land cruiser owner(83 and 95). I recently added a 98 ls 400 to the fleet after eyeing them for years and the car of course came with only the valet key. I have read up on the issues with getting a new master key without having a master key to "copy", but I have to question if it is possible to open up the valet key somehow to get the immobilizer chip out of it, then place it into the master key along with a used button assembly to create a cheaper master key? This idea stems from multiple threads I have read on the subaru forums in the past(also have a 05 STi) with some members wanting to use the 04 STi key on the 05+ STi's equipped with the immobilizer(the 04 key looks much cooler and is made of Titanium).

My ls 400 also came with the shell of the master key with the key already cut, so all I need to buy in theory is the guts of the key. Now this idea is only conceivable if this question can be answered the way I hope, can you program the keyless on the master key without dealing with the immobilizer portion of the assembly?

Thanks!

sha4000

iTrader: (1)

Short answer no, you need the master to program any additional keys to my understanding.

RA40

iTrader: (6)

The master key has a different notch at the tip of the key compared to the valet. I have a thread here with a pic showing the difference. The transponder within as far as I am aware does not relate to anything other than allowing the engine to run.

eld4au6

Err maybe I didn't explain.

I have one valet key that will open the driver door and start the car, I also have a 3 button master key without the immobilizer/ 3 button brain but it is cut for the car and will open all doors plus the trunk and glovebox ect. My idea is to rob the immobilizer chip out of the valet key rendering the valet key useless to crank the car, then put the immobilizer that is programmed to my ecu out of the valet key into the 3 button housing along with used 3 button "guts". Using the 3 button guts only for keyless entry, and use the immobilizer chip out of the valet key in order to start the car.

Luckily I have found a local locksmith that has quoted me $450 for the ecu reprogram along with a new master, plus one dummy key. Does this sound like a pretty good deal? If my valet key idea doesn't work I can also give him my cut master with the used internals to program with the new master I assume?

sha4000

iTrader: (1)

Read this thread, you might be in luck.

https://www.clublexus.com/forums/ls4...-98-ls400.html

RA40

iTrader: (6)

You can do that. So long as this is the same transponder chip, it will not need to be reprogrammed. Succeeding keys will need to be programmed and that is where the key blade is the problem since it will not have that master key ridge on it.

In that instance, my suggestion would be to take your VIN and proof of ownership to your local Lexus dealer and order a master key. (This should be less than the locksmith reprogram and you can DIY key programming/recognition then on.) Then buy any number of transponder equipped keys from that auction site and program them to the car. Keep one master key in a safe place for emergencies.

The programming sequence can be found in the FAQ.
https://www.clublexus.com/forums/ls4...questions.html

LScowboyLS

$450 is a total ripoff for this service, cruise around online and you will find that most legitimate locksmiths get about $125 for this on average - don't get gouged!

eld4au6

LScowboyLS: Do you know of someone in the Birmingham area? I'm in Anniston.


RA40: What do you mean by master key ridge? I have been able to fool the car to start with my master key minus the 3 button assembly by placing the valet key above the ignition. Could I do the same thing to initiate the add key process?

I have a "new" used HYQ1512V mater key to get the button assembly out of and I plan on giving it a try.

sha4000

iTrader: (1)

Did you even read the thread I linked to for you?? The poster said he accomplished it with a valet.

eld4au6

I did in fact, I sent him a pm but haven't heard anything.

mappo

I've got a similar situation, and plan a similar fix. Does this sound like it'll work?

My LS came with only the valet key and what I thought to be a stand-alone button fob for remote functions. Upon closer inspection, the "fob" is actually the upper half of the master key with the metal key stalk missing. I have no idea how or why this is the case, it's just what I got with the car.

I verified that the half-key fob is/was the master key to my car by wrapping the valet key head in foil. With its transponder thus blocked, it doesn't start the car. With the halfkey fob next to it (valet still wrapped in foil) the car starts. So the immobilizer chip in the fob seems to be programmed to my car.

I ordered 2 new master keys pre-cut to my VIN from Sewell. I hope to program them by fooling the car into thinking I have an existing master key using the same foil-and-fob trick. If I wrap one of the new masters in foil to block its unprogrammed chip, and put it in the ignition with the halfkey master next to it, the car should see the two half-measures as one existing master that I can then use to program the second new master key. Once the second key is programmed, I take the foil off the first one and use the second one to program it. Does that sound like it'll work?

RA40

iTrader: (6)

Just as a reference, this is a pic of the master and valet key, master key ridge circled in red

eld4au6

have tried multiple times tonight using this method:
Remote Programming (Tami's procedure in JohnMD's post):

1. Close and lock all doors. Unlock and open driver's door.

2. Put original key into ignition and remove TWO TIMES. (The driver's
door is open during this step)

3. Close and open the driver's door TWO TIMES. (Close, open, close
and open....the door is open at the end of this step)

4. Put original key into the ignition and remove.

5. Close and open the drivers door two times.(Close, open, close and
open....the driver's door is open at the end of this step)

6. Put NEW key into the ignition. Close the driver's door.

7. Turn ignition ON then OFF ONE TIME- this will put the car in ADD mode for
your remote. (Turning the ignition ON then OFF TWO TIMES will ADD the remote
but will erase all existing remotes.) (I turn the new key ON and then OFF
only ONCE as I want to add the new remote and the key. This step is confusing
and is probably the source of my issue)

8. Remove the key from the ignition. The door locks will cycle one time (or two
if you are erasing) . On the REMOTE press and hold the LOCK and the UNLOCK
button for 2 seconds. On the REMOTE press the LOCK button for one second.



AT THIS POINT, the locks should cycle by themselves ONE time. This means the
procedure was accepted. IF the locks cycle twice it has failed. IF this happens
you must start over. Hold the remotes higher up for better reception



9. Open and close the drivers door. Put newkey in ignition and pull
out. This will end programming.


Also tried the lexus tsb with the power lock lock unlock x5, but after two attempts at that 3 of the door actuators were getting weak causing them to double lock.

Any other ideas before I pay for one new master key and ecu reprogramming?

RA40

iTrader: (6)

The valet key cannot be used to add new keys or FOB's. It needs that master key ridge to tell the ECU that it is a real master key. With your hacked valet key and a correctly cut master, you can then add keys and FOB functions. You should not need to have the ECU flashed. That usually happens with completely new set of keys and re-keyed cylinders. Buy the master key through the dealer.