News on my problem.
If could help me, or help somebody later.
I buy a Ktag chinese clone. Around 70€.
With this tool, I could save all ECU information of the break SLK ECU

In same time I do a backup of the ECU of the car. Looking the EEprom file, I notice that ECU was not the original one (ML 3.7 auto from VIN, don't know if map and
Flash are correct or not) => best I think is to use SLK ECU backup.
With SLK spare part, no start, but Fan not go to his maximum speed.
At this time, I think just need to change gear box setting.
I could share the SLKR170 3.2 ECU backup if somebody need ?
I will let you know next results
Have a nice day
Nicolas