Hey guys, I am in the process of "manufacturing" another key for my 2002 Audi A4B6 also. I only have one key so my goal is to have another one that I will keep home, in case I loose the only one I have. Since I have a 2002 model, it seems that my CCM is somehow different from the B7 models so my only option ( without other modifications ) - is to go with a B6 key only. Although the B7 key looks sexier, I won't cut my wrists so a B6 key would be just fine :)
Now, as far as I have read through quite a few threads on this forum concerning this matter , let's sum up what we know so far
( and anybody should correct me if I'm wrong ) :
- the key is actually made out of 2 distinct parts:
a. the key ( blade ) part - which contains the metal blade + the transponder chip that is required to communicate with the car's immobilizer in order to start the engine
b. the buttons ( remote locking ) part - which contains the radio transmitter + buttons that lock/unlock the car's doors/hood remotely.
- you need another key of course - probably I will just get a used one off ebay as they come cheap, some even with blank metal blades mounted. In my case, my key has the following product code : 8ZO 837 231 / 355029 @ 433.92MHz. This is the code found on the buttons half and I do suspect that this is the only code that is important because the other half ( the blade half ) is actually a plastic case containing the metal blade + transponder chip which is the same in all cases ( id48 chip ). On eBay I found keys ( remote part ) working on 2 different freq. : 433.92 and 315 Mhz.
Question 1 :
if the key(s) that already is functional, works on let's say 433.92Mhz, do you necessary need to get the next keys that work on the same frequency or you can get any key to work on any car ?
There are 2 ways to match the key ( remote lock/unlock ) to the car : one way where you require to have your existing key in the ignition and follow some simple steps ( you can find the exact steps on google on tons of websites ) and the second way which is the safest and always seem to work with no problems : use a VAG-COM interface to have the car "learn" the new keys as explained here - http://www.ross-tech.com/vag-com/car...-matching.html
To get the remote to work seems to be the simple part, as dealing with the car's immobilizer in order to have it start the engine requires the other half of the key - the part with the metal blade and the transponder chip. The metal blade issue is actually not an issue, it's pretty straight forward actually : purchase an uncut ( new ) metal blade and have it cut by a locksmith to match the original key's profile. You have to be careful though as there are 2 types of blades : a longer one and a shorter one. On my B6 my blade is a bit longer and according to the forums, the B7 ( and newer ) keys are shorter by a bit so be careful what you buy. Once the blade problem is out of the way, you have to deal with the more delicate problem : how to match the key's chip to be recognized by the car's immobilizer in order to start. There is only one way ( except the dealer ofc ) to program the key to work with the immo : the VAG-COM way as explained here : http://www.ross-tech.com/vag-com/cars/key-matching.html
The problem is, you need a 7 digit SKC ( Secret Key Code ) to do it. Before 2005 Audi either released this code to it's clients on a new car purchase or a client could just ask about it at a local Audi dealer. After 2005, this info is not released to the public anymore ( probably cause of security issues ) and not even a dealer or an Audi technician can get this code as the process of matching a new key to a car in a dealership is done with the car connected to a device that connects to Audi's database in Germany and the sync is done automatically online with nobody seeing this SKC in the process. So how do we get it ? Some say that on some models is written on a paper behind the car's cluster, but 2 guys that took out the car's cluster reported no code. Looks like the only way to get that code is to use a VAG Tacho interface connected to the car and a PC. These can be purchased off eBay. I haven't seen one but it seems that is very similar to a VAG-COM interface cable but is used mostly to re-write the car's mileage display and to read out this code from the car's ECU. I don't know what version should work on what cars but if someone knows exactly, it would be great to share it to us. I would also like people that managed to read out the SKC using such a VAG Tacho cable/interface to relate how it's done and if there is any other software involved other than the one supplied with the cable on a CD upon purchase.
Supposedly we managed to get the SKC code using the Tacho interface. We note it down and follow the Ross-Tech ( link above ) technique to match the new key(s) chip(s) to the car's immo.
Question 2 :
Using VAG-COM, can you match an already used chip ( already in a second-hand key ) to the car or the chip has to be necessary "virgin" ?
If you would go to a dealer to have a key matched, that key's chip would have to be "virgin" ( never used on another car before ) - so when purchasing a used key off eBay you would also have to purchase a new chip to fit in the key you wish to sync to the car. New chips can be found on KeyMam or eBay - search for id48 chips. Some eBay folks, say that ANY chip ( previously used or not ) can be matched to ANY CAR using the VAG COM. I find this to be at least very likely to be true because according to Ross-Tech instructions, with the old key in the ignition, there is a point where the number of matched keys is set to 0 - so all keys are being UNMATCHED which means the old key ( working one ) is now also considered a used key like any others. The following matching process must be completed for both the old working key in the same way as for the new ones. So if it works to re-match your old key, why not work for any other previously used keys ?
So to sum up what's needed : 1 complete Audi Key with a functional remote component, 1 blank metal blade, 1 VagCom interface, 1 Vag Tacho and maybe a new transponder id48 chip.
I hope everything makes sense and I ask you guys to make clarifications where needed... and correct anything I wrongly stated above. Also I would appreciate it for more advanced users to answer my 2 questions above.
Also looking forward to hear from people that actually succeeded all the steps above :)