Downgrade SLK Comand APS Firmware

[Daniele]

Hello.
I'm still searching the net for the older (the first) firmware version for my SLK Comand APS.
The version I'm looking for is:
W171 589 00 22 00 SW-Rel 9.390 Build 15/04

I already have this:
W171 589 03 22 00 SW-Rel 21.090 30/06
I got from an Austrian guy

But before to install that disk I want to be sure I can downgrade the version in the future.

I want to be sure about that because I want to be able to enter the Comand Engineering Setup.

I wonder if the version W230 589 00 22 00 is just the same but for another car and I can install anyway in my comand.
It show the same version and same serial othere then the Wxxx.

Can anyone spot a light on this issue and maybe give me the old version ISO file via email? (Should be compressed like 6/7Mb)

Furthermore.. can someone of you that have an SLK with the lates firmware W171 589 03 22 00 SW-Rel 21.090 30/06 make a trial for me trying holding down 1, 3, 8 keys simultaneously just after COMAND-APS is turned on?

Thank You
Regards

[Diesel Benz]

Could you explain what is it that you want to do with the engineering menu? Must be important to you if you want to compromise over the bug fixes from the later SW.

[Daniele]

Just accessing it