Enable Traversal Audio Cues (Options → Accessibility → Text-to-Speech and Audio Cues → Traversal Audio Cues).
Once you interact with the generator or vehicle, the minigame will begin. You will hear interact cues with faster than average timing.
Time your inputs with the cue. In order to start the motors you need to press interact 3 times in succession.
Characters will also comment when they fail or succeed to let you know your progress.