Object Detection Description and Operation Rear Park Assist

The object alarm module monitors the distance and how close a vehicle is to an object when backing up in a parking maneuver. The object alarm module will notify the driver of any objects of interest when backing up at speeds less than 8 km/h (5 mph). The distance between a vehicle and an object of interest is monitored by 4 ultrasonic sensors located in the rear bumper of the vehicle. The object alarm sensors receive the echo signal reflected off an object of interest while the vehicle is backing up at speeds less than 8 km/h (5 mph). The object alarm module receives the vehicle speed from the ECM via the serial data circuit. When the backing up speed exceeds 8 km/h (5 mph), the object alarm system is disabled. The object alarm 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 BCM controls the object alarm system chime function and sends serial data requests to the radio to sound the chime as needed. The visual display comprises of two amber and one red indicator and these indicators illuminate based on the vehicle distance to the object of interest. When the ignition is ON and the vehicle is placed into REVERSE, the object detection system performs a bulb check on the rear display.

The rear object alarm systems are equipped with 4 ultrasonic sensors located on the rear bumpers of the vehicle. These sensors are used to monitor how close the vehicle is to an object. The object alarm sensors receive the echo signals reflected off an object of interest while the vehicle is backing up at speeds less than 8 km/h (5 mph). The object alarm sensor is a 3-wire sensor comprising of the supply voltage circuit, signal circuit and the low reference circuit. Power is provided to the object alarm sensor via the supply voltage circuit from the object alarm module. The object alarm module also provides ground to the object alarm sensor via the object alarm sensor low reference circuit. The typical object detection alarm sensor signal voltage when the system is active is between 7.2-9.2 V.

The information center telltale assembly visual display comprises of two amber and one red indicator. These indicators illuminate based on the vehicle distance to the object of interest. When the ignition is ON and the vehicle is placed REVERSE, the object detection system performs a bulb check on the rear display. When a malfunction exists in the object alarm system, the object alarm module illuminates the information center red indicator continuously. The object alarm module provides power to the rear information center telltale assembly. The object alarm module controls the information center indicators by providing ground via the indicator control circuit when active.

When the ignition is ON and the vehicle is placed into reverse, the object detection system performs a bulb check. During the bulb check, the 3 indicators on the rear display will illuminate for approximately 2 seconds to indicate that the system is working. The object detection system performs a bulb check and operates when the following conditions are present:

The object detection system senses how close the vehicle is to an object. The distance is determined by the 4 ultrasonic sensors located in the rear bumper. When the system detects an object while the vehicle is in reverse, one of the following will occur:

The object detection system can detect objects 7.6 cm (3 in) wide and at least 25.4 cm (10 in) tall. It cannot detect objects above the level of the roof.

If the object detection system detects a malfunction, the object detection system sends a serial data message to the instrument panel cluster (IPC) to display SERVICE PARK ASSIST on the driver information center (DIC). The chime will sound and the red indicator on the information center telltale assembly illuminates continuously, notifying the driver that a malfunction exist.

SERVICE PARK ASSIST

The driver information center (DIC) displays SERVICE PARK ASSIST when the object alarm module detects a malfunction in the object detection system and sends a request to the DIC for display of the message. The DIC also displays SERVICE PARK ASSIST when there is a loss of communication with the object alarm module.

PARK ASSIST DISABLED

The PARK ASSIST DISABLED message is displayed in the DIC when the object alarm system is disabled due to conditions that disable or inhibit the system. The object alarm module requests the DIC via the serial data circuit to display PARK ASSIST DISABLED when it detects that one of the following conditions is true: