What to do if you don't have the master key?

[lockeyboy]

Does anyone know how you get a second key cut/coded if you only have one working key(of which the fob doesn't work/light up) and you don't have the master key?

Can you just buy a. Lexus key and get it cut, which would at least open and close the car or would it need to have some coding to work?

mk4 key (key with fob all in one)

[ambermarine]

As far as my memory serves this subject as come up several times on the forum,and the end result is an expensive visit to Lexus.

[lockeyboy]

9 minutes ago, ambermarine said:

As far as my memory serves this subject as come up several times on the forum,and the end result is an expensive visit to Lexus.

Hopefully not!

I did call them yesterday but they also need the master key 

there must be a third way...

[Cotswold Pete]

Have a look at this posting - http://us.lexusownersclub.com/forums/topic/75877-programming-ls400-keys/  - sounds like if you can find another key with the electronics in it, you might stand a chance.

 

Also found this  http://www.keyfobprogram.com/1999-lexus-ls400-remote-programming/

 

As far as I can tell a Master Key is a key which has the electronics in (you get two of these when you buy a new Lexus).

I would guess a Lexus port of call is going to see you spending North of £200, had the same issue with wife's Honda a few years back, but they wanted £250+ (about what the car was worth).

 

[Newbie1]

Going through this at the moment. First thing to remember is that there are two aspects to key programming. One is programming the transponder chip that is in the key (whether that's the combination fob key or just the black key without fob.) This is the most essential part as the transponder will deactivate the immobiliser. If you can't deactivate the immobiliser you are really in trouble and will be looking at replacing the ECU, immobiliser unit and associated keys (all three are coded to each other) from either a scrappy or new. There is a process for programming the transponder in a new key on this site or elsewhere. The second part is programming the key fob to open/close the doors and boot (and presumably setting the alarm). Again, the process is described on here or elsewhere. This second process is also the subject of a Toyota Service Bulletin.

Lexus will charge you several hundred pounds to provide a master key fob, cut to the correct pattern (from their records.) You will need to produce the certificate of ownership for this part. The electronics will not be programmed and they will thus ask you for another £80 or so to program them. I might end up doing this if the next LS400 key fob I have bought second hand does not work. I could not program the first one despite it being from another Mk4 LS400.

[lockeyboy]

My current key situation is one functioning key that opens closes and starts the car, but doesn't work remotely or appear to light up. Previous owner says he's changed the Battery but I would have thought t would light up even if not sending a valid signal to the car?

 

the second key is here...

 

 

[Newbie1]

Ok. You have a master key, as it starts the car. It is a fob master. There would also have been black a non-fob master key that would start the car, now lost. Regardless, you only have one transponder chip coded to your ECU and immobiliser. Lose that and you are out of luck. Either get a used key of eBay ( making sure it is the correct Denso 'C' type chip) or go the Lexus route. The remote opening fob may have died but it is not your priority; getting a new key with programmed transponder is.

[Newbie1]

To add, you would need to get the key cut and insert the used, newly programmed fob 'guts' into the newly cut key case. Empty fob cases with key blanks are available on eBay.

[jonno]

Only one key on purchased  LS400 so I bought blank three button one on eBay for about £4.00 and had it cut, fitted and programmed for about £90.00 by local car key chap. Works fine.

[Newbie1]

Interesting. Mark 4? Who was the seller? I've tried two of the key blanks with fob from eBay and despite them being labelled as Denso neither could be programmed for the transponder or the doors. A seller of one that works would be valuable information.

[jonno]

Yes, a Mk.4 but I think it was just the blank key with no transponder ( if thats the squarish inner bit ). i'd bought the key before seeing the guy who did the business but he also provided  blank keys. A very experienced chap who seemed to spend most of his time programming keys and getting into locked cars so he might be worth having a chat with. It was a while ago so the details are a bit hazy. I have no other connection to him

Elite service centre, malvern. 01684 561100

 

99

99 Barnards Green Road
Malvern
Worcestershire
WR14 3LT
UK
Tel: 01684 5611Barnards Green Road
Malvern
Worcestershire
WR14 3LT
UK
Tel: 01684 561100

[lockeyboy]

Just to keep this thread going, I am now in possession of two fob keys and a solid key.

ive swapped out one Battery (cr1616) and the fob now lights up, however the car does nothing.  It still opens and closes with the key

is it possible I need to re code the key or more likely that the transponder in the car has given up?

[Newbie1]

So you still can start the car with a key you have?

[lockeyboy]

Yes or at least I could before I put the new Battery in

ive not tried it other than to open and lock the doors since replacing just invade I set any alarms off and annoy the. Neighbours