Fuel Pump Relay control (ECU provides ground to activate the relay). Motronic 1.5 & 1.5.4 (Common in Opel/Vauxhall)

Key concepts

Pain level: 2/10 – These are surprisingly logical. Power on pins 18 & 35, grounds on 19 & 20. Injector drivers on pins 14-17. Ignition output on pin 1. A beginner can learn this in an hour.