The Bosch ME20 belongs to the Motronic family, combining ignition and fuel injection control into a single unit. Commonly found in vehicles such as certain Opel/Vauxhall models and specific Toyota collaborations (often utilizing similar architecture to the ME17 or ME9 families but with distinct calibration), the ME20 is an ECU that demands precision. Unlike older ECUs, the ME20 usually employs a more complex architecture with greater integration of throttle control (Electronic Throttle Control or "E-Gas") and OBD2 compliance.

Pin 4 is generally used for the ignition switched signal.

Before diving into the pinout, you must identify which ME20 sub-version you have.

Knowing the verified pinout opens up several possibilities: