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Introduction

Welcome to the BMW-DME-M3.3.1 wiki! I have no business near the programming side of a Bosch DME professionally. I have some experience in mechanical engineering revolving around fuel system design. That said take everything here as a theory intended for education and research ONLY. Any use of the information is AT YOUR OWN RISK

Historical Context

This project is crowd sourced information focused on the reverse engineering of the ROM stored in the DME(ECU) of BMW OBD1 cars that used Bosch M-Motronic 3.3.1. Commonly used on e34 and e36 BMW cars with m50/M50tu/S50 engines. These cars are almost all 30+ years old. The information that has been out is starting to disappear as websites/forums change and disappear. The information has never all been in one place. It is spread across hundreds of web pages. Some information on other versions of the Bosch system is also relevant in some cases. Older and newer system information can be leveraged to either learn more about the target M3.3.1 system or add to the systems capability.

M-Motronic system overview

• The M-Motronic book from Bosch

• Wiring schematics

• Pinouts

• Sensors

Technical Specifications of DME 3.x

• Educated Guesses

Reverse Engineering Process

• Software disassembly

• Scoping the system

• Bench running the DME and hardware simulation

• Software Simulation

Hardware versions of M3.x

• The cars and DME hardware

Software Versions of M3.x ROM

• Version descriptions

• Rare Versions and BMW update capability

• e34/e36 413-609/623/715/744

• e36 M3 506-965

• Alpina B3 413-a677-1

Structure of the ROM

• ...TBD

Applications

• Engine Swaps

• Offroad/Race tuning

• Calibration for part changes and forced induction

Evolution and Future Trends

• Professional tuner development

• What about the DIY community

The Code Theory

• ...TBD

Conclusion