The PFSYNC-1 On Scene Sync Module works in conjunction with any Pathfinder Siren to provide synchronization between multiple “like-programmed” vehicles. On Scene Sync Module uses a GPS signal to maintain timing between vehicles providing the capability to synchronize warning lights, and voice messages to unify the visual and audible warning of multi-vehicle response. An ambient light sensor is also included in the On Scene Sync Module to auto-adjust warning lights.