Yes, what systems and parts depend specifically on the ECU to function if a different drivetrain is fitted having its own ECU and TCU. Or is it possible to retain the factory ECU solely to operate non engine and transmission functions although that would require use of the factory key system I guess, perhaps electrics could replace the vacuum bits. Where I live it would be illegal to use a Mercedes V8 conversion so that's out of the question.

 

Hi, what sort of drivetrain do you want to put in it? There's no problem with using Mercedes stuff, that's what's already fitted to them. I've completed a few V8 crossfire conversions and they've all been approved. I live in Brisbane and can do ECU/TCU modifications and tuning. Send me a PM and get in contact with me if you've got any questions.

 

After doing lots of research it seems like the best way to go is to get a harness for the new ECU and just use the Mercedes body wiring where it's suitable and where not incorporate some custom wiring. Keep it simple with relays and a fuse box and toss any old non-essential units that are Mercedes specific. That seems to be the best way to minimalise future problems with old systems and parts too.

 

Thanks for the offer Andrew, I'll start a new thread once the project begins.