PC 3.1: reconnect the SELV and the service plug in the correct order and reactivate the vehicle. Order is manufacturer-specific, but the common logic is the mirror of safety: the HV path is completed first while everything is dead (service plug refitted, fully seated and locked so its interlock closes), and then the 12 V negative terminal — the trigger — goes on last. Gloves stay on for the plug refit. Confirm the work area is clear, covers are back on, nobody is near orange cables, then power the vehicle to READY and watch the instrument cluster like a hawk: the first ten seconds of warning lamps tell you the story of your own workmanship.