Pinouts vary significantly between versions. Always verify your specific ECU part number.
Open the passenger footwell (often under plastic trim) or engine fusebox. The ECU has a label like: Bosch 0 261 203 412 or 0 261 204 167 (ME7.5) bosch motronic ecu pinout
Search Signal: [ Type here... ] (e.g., "O2 Sensor", "Fuel Pump Relay") Pinouts vary significantly between versions