Sorry, guess I tend to mix hobbies. Used to design/program aircraft engine and flight control computers at the machine or assembly code level. Have also designed microcode for bit slice processors. Later I did a bit of unmentional work for my employer. Have been reprogramming my cars since a 84 Fiero but was entirely GM CCC and then P4 computer systems. These were mostly Motorolla 68x based systems with demountable UVProms.& EEPROMS (if geek speak I do not know how to translate.

That said the process is the same:
- identify the architecture (processor, memory, etc.)
- extract the memory contents
- identify the change you want to make
- make the change to your copy
- reload the memory with the new contents.
- test

Now I have not looked deeply into the SKREEM module but from what I have seen my hypothesis of operation is like this:

- key is inserted and turned
- SKREEM notifies ECU
- ECU responds with an "encrypted" VIN
- SKREEM compares with its memory
- SKREEM responds with GO/NOGO
- If GO ECU enters start sequence.

Now what I meant by the JMP (Jump) command was if when the ECU receives the interrogation (which may need to be simulated - have to look at the programming) if the ECU just skips the rest and goes directly to START , job done.

Once upon a time I did a lot of reprogramming of WRT routers and have a stack of bricked ones so would not like to repeat that with my car so once I figure out what needs to be done then would require a test bed (or will tell someone else what to do, I just need the dump).

From what I have seen EUROTUNES has a programming device for Mercedes but does not seem to be available for sale. Anyone either have one or know what it is or about a KESS V2 ? Might be able to uses a MegaArduino to create an interface.

Does this help ?