Bosch Motorsport and Turner Motorsport have teamed up to offer a plug-and-play, tunable ECU system for the E46 M3. The Bosch Motorsport ECU opens the doors for unlimited tuning potential and instant power and reliability benefits over the stock BMW ECU. The new plug-n-play ECU cuts through all of the hassle and additional work that normally comes with switching to a standalone management system.

The new ECU offers immediate power and torque gains, full access and control over engine mapping, low cost compared to other engine management systems, no interference or limp modes from factory ECU, base map file included (the Bosch ECU can hold 3) and access to upgrade-specific map files and updates.


To get reliable power means removing interference from emissions equipment or OBD oversight and eliminate the possibility of a race-ending limp mode or fault code. The Bosch ECU system eliminates layers of complexity to give you what you really want: power and control. The new ECU system gives you all of the control of a stand-alone but works with the existing wiring and sensors in the E46 M3, including the instrument cluster and dash.

The special translator interface box allows the Bosch ECU to communicate with the stock VAN0S, drive-by-wire, cooling and oil systems, ABS, and more. The Bosch ECU works with their LSU4.9 wideband oxygen sensors which replace the two stock pre-cat O2 sensors. Turner strongly recommends that you replace your spark plugs and ignition coils with the latest BMW part numbers before installing this system.


Bosch’s ECU system comes pre-installed with a base engine map that closely matches the existing engine spec. The multiple tuning maps were developed on Turner’s Dynapack chassis dyno using popular bolt-on S54 power upgrades: headers, intakes, cams, superchargers, etc. Initial test showed that the supercharger file gained almost 50hp over the tune included with the supercharger kit. A 3.5L stroker engine gained over 30hp from the best file supplied by the engine builder. The owner can make unlimited adjustments to optimize the output using the Bosch PC software.

Bosch Motorsport E46 M3 ECU System includes:

  • Bosch Motorsport MS4.0 ECU
  • E46 M3-specific Translator Box
  • Bosch Motorsport LSU4.9 wideband Lambda sensors (x 2)
  • Turner Motorsport base software tuning file

Optional items:

  • Expansion Harness – for data logging and aux port
  • Bosch MSA interface for connection to laptop/PC