Question about Key Coding

[Theiceman]

hello All .

I have read a fir bit about key coding on our cars and I find of It confusing. I have read that you can train a key by putting it in the keylock and training it . I have also heard you have to take it to the dealer as they still control this. I have also heard rumors key coding can be done with vcds although I am not sure how.

The situation is I only have one key and my buddy just wrote off his car and still has his spare key. I have a spare blade which I will have to get cut somewhere, but then do I have to take it to the dealer to get it coded to my car ?

Thanks.

[mtroxel]

There are two types of key coding:

1. The immobilizer chip has to be coded at the dealer. Your instrument panel and ECU have to see and recognize the chip in your key. If they don't, car shuts down and you have to tow it to the dealer. Can't be done with VCDS - dealer only.

2. The remote door-open part of the key is less fussy. That can be done with VCDS or or can also be done by the old key in ignition blah, blah, blah procedure you've seen.

I have to recode per #2 every time I disconnect the battery. I've never had to mess with the immobilizer, but you'll have to if you want your buddy's key to start your car.

[Denio24]

hello All .

I have read a fir bit about key coding on our cars and I find of It confusing. I have read that you can train a key by putting it in the keylock and training it . I have also heard you have to take it to the dealer as they still control this. I have also heard rumors key coding can be done with vcds although I am not sure how.

The situation is I only have one key and my buddy just wrote off his car and still has his spare key. I have a spare blade which I will have to get cut somewhere, but then do I have to take it to the dealer to get it coded to my car ?

Thanks.
Contact tom @speedosolutions.

If youre looking to code another key it will be difficult, and requires a specialty tools to get the ecu pin and some other values. You cant just code via vcds as it is immo4. Also, you will need a new transponder id48 megamos crypto for the fob chip as b7 transponders cant be reused. Tom can also help you with that.

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[Theiceman]

Contact tom @speedosolutions.

If youre looking to code another key it will be difficult, and requires a specialty tools to get the ecu pin and some other values. You cant just code via vcds as it is immo4. Also, you will need a new transponder id48 megamos crypto for the fob chip as b7 transponders cant be reused. Tom can also help you with that.

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as this is all kinda new to me you are saying I can NOT just program another b7 key to work with my car at the dealer ? they are one use only ?

if that is the case it may be just easier to go to the dealer buy a key and have them program it. having only one key for my car makes me nervous so may be worth it for piece of mind.

[BenMTL]

You cant just code via vcds as it is immo4.

I thought my VCDS can do IMMO programming and it can, but since our cars are IMMO4 like you say, I can't program keys for B7s, only older cars;

http://wiki.ross-tech.com/wiki/index.php/Immobilizer#Immobilizer_Generation_4

UNLESS....The key has never been programmed before (new OEM blank)?? Reprogramming is impossible however it seems? See Ross-Tech's chart.

That is consistent with what I've heard discussed in a few different threads on here as well...

[Theiceman]

okay I have done a bit of reading googling the terms Denio was using.

There is some small crystal that needs to be replaced in the key itself to essentially to make it a " born again virgin" . then I can have it programmed and the new key blank cut. The crystal I need is a "ID48 megamos crypto" .

Once I get these I should be good to go .

DO I have it all correct Denio ?

Il reach out to Tom and see if he can help.

Thanks All.

[Denio24]

It's a little more complicated than that since our ECU utilizes a secret challenge key for the immobilizer. Each time the ignition is started with the key in the on position it cycles through the same encrypted algorithm and produces another key. I don't know the value of this key and it must be retrieved using special read tools, same with the pin. I'm sure VCDS can help with the process of coding a new key in some way, but I know as a fact that you wouldn't just be able to do it with VCDS and a new cut key and transponder. Like i said, transponders cant be reused. Programming keys on B6 is alot easier as there is only the ECU Pin to deal with, you're home free from there and able to code the new key using vcds. Dealer will surely charge more...i'm thinking an insane amount. [:D]

You probably can't do it yourself, so i would just go to http://www.speedosolutions.com/ and he will definitely help you. Very nice guy!

[Theiceman]

It's a little more complicated than that since our ECU utilizes a secret challenge key for the immobilizer. Each time the ignition is started with the key in the on position it cycles through the same encrypted algorithm and produces another key. I don't know the value of this key and it must be retrieved using special read tools, same with the pin. I'm sure VCDS can help with the process of coding a new key in some way, but I know as a fact that you wouldn't just be able to do it with VCDS and a new cut key and transponder. Like i said, transponders cant be reused. Programming keys on B6 is alot easier as there is only the ECU Pin to deal with, you're home free from there and able to code the new key using vcds. Dealer will surely charge more...i'm thinking an insane amount. [:D]

You probably can't do it yourself, so i would just go to http://www.speedosolutions.com/ and he will definitely help you. Very nice guy!

ok thanks , i sent them a message to see what can be done. Im thinking I might have to send them my whole cluster ?

[mtroxel]

ok thanks , i sent them a message to see what can be done. Im thinking I might have to send them my whole cluster ?

See what Tom says. Good guy....but it involves the ECU also so see what he says.