E46 Medic
ECU MS43
Ok so this is the most interesting part of the journey. The control of the entire machine is inside this box and you can mess with all of it. BMW did not go way out of their way to prevent it in this older platform and some real smart folks have built some real cool tools to help get this done.
You can do things like deleting components such as the EWS immobilizer and the secondary air pump. You can also change the tune and increase the performance. Of course as you start messing with stuff you can diminish the soft drivability of the car.
I began with headers and a stage 3 tune and melted the cats and all that. After seeing how unruly the car had become I decided to roll this back a bit. I put the cats back on and upgraded to ZHP 3.0 and i really like it the way is is now. Got some good punch but it’s still drivable.
In and case, you can find all you need at MS4X.net. They have all the tools and some binary files to start with. I bought a couple of used MS43 boxes on eBay and messed with them for a while until I started to get what I wanted. I’m still messing with it to delete EWA and work further on the tune. It’s a ton of fun.
