A vehicular vision system includes an image sensor and an image processor. The image sensor is disposed at a vehicle and has an exterior field of view. The image sensor is operable to capture image data. The image processor is operable to process captured image data. The vision system is operable to automatically synchronize the image sensor to an ECU reference timing. The vision system may power on the image sensor synchronous to the ECU reference timing, and the vision system may regulate the timing of the image sensor synchronous to the ECU reference timing. The vision system may regulate the timing of the image sensor between a fast mode and a slow mode to synchronize the timing of the image sensor to the ECU reference timing.