A vehicular rear backup system includes a rear backup camera and an electronic control unit (ECU). The camera connects with the ECU via a cable. Image data captured by the camera is converted at a serializer of the camera to serialized image data. The serialized image data is carried to the ECU via the cable and is de-serialized at a de-serializer of the ECU to form de-serialized image data. Responsive at least in part to processing at the ECU of de-serialized image data, the vehicular rear backup system is operable to detect an object present rearward of the vehicle during a rear backup maneuver. Video images derived at least in part from an output generated at the ECU via processing at the ECU of de-serialized image data are displayed at a video display device of the vehicle during the rear backup maneuver of the equipped vehicle.