Use this page as a quick reference for factory MS41 wiring and the inputs/outputs commonly repurposed for MS41.3. Factory wire colors are listed where confirmed in the official BMW E36 wiring diagram. The official BMW E36 wiring diagram will be attached at the bottom of this page for download and reference. Factory Tuning-Related Pins Pin 7 Function: MAF Ground Color: SW — Black Pin 8 Function: MAF Signal Color: GE — Yellow Pin 10 Function: Coolant Temperature Signal Color: B

Download and set up the software and definition files needed for BMW MS41/MS41.3 tuning, including RomRaider, QuickFlash, ECU definitions, logger definitions, and supporting files.

Before changing fuel maps, ignition timing, injector scaling, or any other calibration parameter, you need a reliable way to communicate with the ECU. A basic MS41 tuning setup consists of a Windows computer, compatible USB-to-OBD interface, tuning software, MS41 definition files, flashing software, and a stable electrical system. OpenMS41 lists four basic requirements for reflashing an MS41 ECU: MS41 QuickFlash ECU cable RomRaider Write access enabled This section will get t

BMW MS41.3 Tuning Guide Start Here BMW's Siemens MS41 platform is a capable factory engine-management system for modified BMW six-cylinder applications. Through the research and development documented by the OpenMS41 project, MS41 can be read, flashed, logged, and calibrated using software such as RomRaider and MS41 QuickFlash. OpenMS41 primarily documents: • MS41.0• MS41.1• MS41.2 Much of the original tuning and reverse-engineering work was centered around MS41.2. The FergZ

How to tune VANOS : 1. log Load and RPM with VANOS always disabled in RR. do a WOT run to rev limiter 2. log Load and RPM with VANOS always enabled in RR. do a WOT run to rev limiter 3. create XY Line Charts and note the RPM at which the curves intersect at high RPM 4. set VANOS to turn off at this RPM in the final tune In the graph below these two curves intersect at ~ 6000RPM. That is the ideal point to turn off VANOS for this engine.