Parking Assist System (PAS) is an electronic system designed to provide an acoustic tone informing the driver of obstacles at or near the rear of the vehicle during low speed manoeuvres such as parking. The PAS consists of two ultrasonic object sensor assemblies mounted to the rear bumper fascia, and an electronic control module buzzer assembly mounted to the side of trunk. Sonar is used to detect the presence of obstacles within a defined area by measuring the time between the transmission and reception of sound waves.

When reverse gear is selected, the sensors transmit short ultrasonic pulses and then listen for an echo reflected from an object within range. The electronic control module uses echo data from one or both sensors to calculate the distance to the obstacle. The PAS only signifies the closest detected object.

When the ignition is on and reverse gear is selected, a tone will sound from the buzzer (1 time for 0.05 second). The control module provides a voltage to each sensor sequentially which is converted into an ultrasonic pulse. Where an object is within the detection range, the ultrasonic pulse is reflected (echoed) and received by the same and/or adjacent sensors. The echoes are amplified, processed and returned to the control module as a digital signal. The control module processes this information and informs the driver of the object by activating an intermittent acoustic tone through the buzzer. The two sensors are mounted onto the rear bumper fascia in an arrangement that provides a slight overlap of the polar patterns. This provides the best coverage of the detection area. The maximum detection distance is 120 cm.