An electronics device is configured for installation in the brake light circuitry of a vehicle braking system. The electronics device is particularly configured to provide a flashing or pulsing appearance for a brake light, such as an automobile CHMSL. The pulsing is accomplished in a precise manner and that provides additional operational safety features than standard automotive brake lights. The electronics device is configured to avoid over-triggering of the pulsating lights due to multiple application of the automobile's brakes in a short time frame. The electronics device is further configured to function correctly even if the automobile is equipped with sophisticated computer systems that analyze the brake light circuitry, and is configured to avoid detection as a problem by the vehicle's diagnostic systems. At the same time, the electronics device will still allow the vehicle's diagnostic scans to detect any actual problems with the brake light system without hindrance.