OpenMS41

About this Project

OpenMS41 provides a shared repository for understanding the Siemens MS41 family of ECUs (MS41.0, MS41.1, and MS41.2) for the purpose of providing the hobbyist with the means of tuning and calibrating their own ECUs. Most of the research thus far has been for the MS41.2 variant.

The MS41.2 OBD2 tuning project was started by me (Abhishek Shinde) in August 2012 and slowly worked on over the years in my spare time.  Many tables have been found for the MS41.2 ECU used in a 1996-1999 USDM M3 and the ability to write to the ECU has been developed by Kim Freding, as well as Kyle (busterhax) who has developed MS41 Quickflash.  Since then, several people have used the definition files I've provided to tune their 6 cylinder BMW engines; some even with Forced Induction!

Dale Schultz is our RomRaider implementation expert and has made huge advances in the ability to datalog the ECU based on information discovered by Mika and Alec.

Murray Allen was able to develop a much faster method of datalogging an MS41 ECU by experimenting with alternate ways to send serial messages to it. The result is a much more user-configurable data stream and speed can be as high as 15-18Hz depending on how many variables are logged. Though, for typical tuning purposes enough variables are needed to bring this down to about 10-12Hz, which is still sufficient for being able to tune most engines in 3rd or 4th gear.

Of special note, is Alec (d_munter) who setup the raw hex code in IDA and interpreted the disassembled code to identifying various functions/subroutines.  Together we have used the reference documents to generate a lot of understanding of the ECU logic as well as defined a lot of maps. This project would not have been possible without Alec!  He has taught me a lot about disassembly, which I have used to further analyze the code, as well as write my own custom code.

Original Contributors

Abhishek Shinde - mrf582

Alec - d_munter

Kim Freding - xbyte

Dale Schultz - dschultz

Mika - pheno

Kyle - busterhax

Abel - Enabled

renneimer

Tom Kelly

Dave

EVILM3666

Todd Williams

Robert

Murray - ba114

???? - pazi88