What is Bosch MD1?
Bosch MD1 is a family of engine control units used in a range of applications. Diesel vehicle examples include BMW applications covered by BitSoftware and the Audi and Volkswagen MD1 CS004 systems listed in Bosch diagnostic software documentation. Bosch's MDG1 research describes a scalable powertrain ECU platform. The ECU designation alone does not identify the engine, hardware or software.
Torque or injection quantity?
For the diesel vehicle applications discussed here, MD1 is generally best understood as torque-oriented. The ECU coordinates requested and permitted torque, then relates the result to the injection quantity (IQ) needed to produce it. BitSoftware's BMW diesel MD1 coverage lists requested torque, torque limits and injection quantity derived from torque. Fuel quantity, injection timing and available air still matter. The exact calculations, maps, limits and units depend on the application.
Basic functions
Depending on the vehicle, the ECU can manage fuel injection, rail pressure on common-rail systems, air and boost, exhaust-gas recirculation, starting and idle, diagnostics, torque interventions and fitted exhaust aftertreatment. Sensors and other control units supply information used in those decisions.
Family scope
This introduction focuses on diesel vehicle applications. Do not assume that all MD1 hardware has the same fuel system: Bosch also describes the MD1CE200 for large diesel, gas and dual-fuel engines. Identify the engine, injection system, ECU hardware, software and installed emissions equipment before applying a definition or procedure.
Continue with MD1 torque fuel and tuning basics for the request-to-fuel flow, the torque model, common limits and diagnostic context. Compare Bosch EDC17.
Sources
- BitSoftware: Bosch MD1 module. First-party description of available BMW diesel MD1 calibration functions; it does not define every MD1 file.
- Bosch diagnostic software update 2020/3.01. Lists MD1 CS004 engine management for Audi and Volkswagen; a diagnostic coverage list, not a vehicle fitment guarantee.
- Rueger and others: MDG1, the new scalable ECU platform from Bosch, FISITA 2012 proceedings, Springer, 2013. Platform overview; abstract publicly available.
- Bosch: electronic engine control unit for large engines. MD1CE200-LE fuel-system and application scope. Sources accessed 10 November 2026.