Hi guys,

It seems the terms pincode, SKC, CS bytes are used by many people to describe the same thing: gaining security access to an ECU.
Can someone explain exactly what they are and how the differ from eachanother ?
(And how they are used in the underlying protocol?)

This is what I've gathered so far:

Pincode is a 4 or 5 digit value, which was originally used to gain access to an ECU.
In the KWP2000/UDS protocol, when the seed is received (27 xx, 67 xx) then the pinvalue is ADDED, and the new value is sent back as the key (27 xx+1).
To gain a different security access level a more complex algo is used, not a simple addition.
When entering the pincode in VCDS, this simple addition is done.

Then later VAG introduced the SKC value (7 digits) which is encapsulates the original pincode, and a workshopcode and a date.
So it is my understanding that if you have a SKC value and you know the corresponding wsc and date, then you can retreive the original pin value again?

What are CS (component security?) bytes and how are they used?
I read they are 8 bytes, and the 8th byte is always fixed?


Thanks for any answers,

H2Deetoo