Circuit/System Description

The object alarm system monitors the distance and how close a vehicle is to an object when backing up in a parking maneuver. The object alarm system will notify the driver of any objects of interest when backing up at speeds less than 5 km/h (3 mph). The distance between a vehicle and an object of interest is monitored by the 4 ultrasonic sensors located in the rear bumpers of the vehicle. The object sensors receive the echo signals reflected off an object of interest while the vehicle is backing up at speeds less than 5 km/h (3 mph). The rear object sensor control module receives the vehicle speed input from the ECM via the vehicle speed signal circuit. When the backing up speed exceeds 5 km/h (3 mph), the rear parking aid (RPA) system is disabled. The object detection system uses visual displays and audible warnings from the radio speakers to warn the driver of an object of interest within the defined field of view. The Rear Integration Module (RIM) controls the RPA chime function via the chime control circuit and sends serial data request to the radio to activate the chime as needed. The visual RPA display comprises of two amber and one red indicators and these indicators illuminate based on the vehicle distance to the object of interest. When the RPA system is activated, the RPA display first performs a bulb check before any normal operation. The object sensor is a three wire sensor comprising of the supply voltage circuit, signal circuit and the low reference circuit. Power and ground is provided to the object sensors from the rear object sensor control module via the object sensor supply voltage circuit and low reference circuit. The object detection system is initiated when the rear object sensor control module receives the transmission reverse input from the RIM via the backup lamp supply voltage circuit.