We cross-referenced , live bench testing, and real-world breakout measurements to confirm every critical pin.

: Multiple ground points exist, such as Pin 3A or 8A.

After extensive research and verification, the following pinout has been confirmed for the Bosch ME20 ECU:

Check the full verified diagrams on Bosch Me20 Verified for high-res layouts. Option 3: The "Tuner Pro" (Best for Instagram/Blog)