Spare Key

[Longtimefan]

John, I'm with you on this, in fact I'm about 6 fathoms down.

[john]

Well for you and me Robin that is WAY over our heads!��

[Stradale493]

I'm reasonably confident I could produce a working transponder chip for the green labelled box if I was emailed a dump from the memory chip. Also a good probability I can extract the 5 digit security code if needed. Only way to confirm it would be to try one.
I may pick up another off eBay to prove my technique.
Still trying to translate that knowledge to the white label box which looks like it stores the codes in the same location but uses a different algorithm (or substitution cipher) to translate it into the actual pin code

[Longtimefan]

Graham, are you talking about the chip in the key here, and how do you create a 'xxxx' via email? It all sounds very complex, and that I would need very technical assistance to achieve success !!

Robin

[ah_sprite]

how do you create a 'dump' via email?

I think you ought to edit your question before Norm arrives on scene!

[Normb666]

That very comment means I don't have to say a thing...

[Stradale493]

Graham, are you talking about the chip in the key here, and how do you create a 'xxxx' via email? It all sounds very complex, and that I would need very technical assistance to achieve success !!
Robin

The process involves reading data from a memory chip in the immobiliser box. It's simple enough to do but does require specialised equipment. That's why the people who do this professionally have a mail order approach where customers send them the immobiliser box. I didn't like the idea of mine getting lost or damaged in the post so would have gone with a local option.

[NoCorseChris]

Mmmm, interesting. The donor for my project came with 2 keys, but one was the valet key, so pretty useless as it stands. If I could make it a working key that would be great.

Did you DIY the data dump from the CODE box? If so, would you share the details so I can replicate it please?? I have the green label version too.

...and of course, you can guess the next question!! Would you be able to program me a transponder given the data?

I suppose another route would be if it’s possible to clone the good key directly?

[Stradale493]

I'm happy to have a go a burning a new transponder key chip - the blanks only cost a couple of quid so its no real loss if it doesn't work.
The hardware I have for burning new key transponder chips can read existing keys but for some reason can't copy they directly and can only produce new transponders using the data dump from the immobiliser box.

The process to extract the data is reasonably straight forward and I found it on one of the Alfa forums
The required data is stored in the 93c56 eeprom chip (in the blue square), and as I don't fancy removing it to read it and then re-soldering it afterward I am reading it with it in place on the board. When reading the data in this way it is suggested you short-out the oscillator crystal next to it (in the red square). As the crystal legs stick out quite a bit I just rest them on a coin while reading the eeprom. Photo is of a white labelled box but the circuit board layouts are the same.

To read the data from the eeprom I am using a reasonable cheap-and-cheerful USB eeprom programmer hooked up to my laptop and a test-clip (for soic8 format eeproms). Just make sure the eeprom programmer is compatible with 93 series eeproms as the really cheap ones may not be.


When the hex data has been successfully read from the eeprom (in 16 bit mode) it should look like this screen shot.
The 5 digit security code is contained in the string of characters I've highlighted (needs to be decoded using what looks to be a substitution cypher rather than a calculation).


Hopefully that all makes sense.