Parking Assist Operation
A problem sensor may be located at the front or the rear of the vehicle by identifying the frequency of the beeping tone. The rear park assist gives a lower frequency tone compared to the front park assist.
When an object is within the measuring range of the sensor, the ultrasonic pulse is reflected and is received by the sending or a neighboring sensor. The sensor converts this signal into a voltage signal and sends this signal to the front and rear parking assist control module. The front and rear parking assist control module evaluates the received sensor signals. As soon as an object is within the measuring range, the front and rear parking assist control module sends a message via serial data to the radio in order to give out the acoustic distance signal.
The measuring range of the front object sensors is between 30-120 cm (11.8-47.2 in). From a distance of 120 cm (47.2 in), the acoustic signal is active. The frequency of the beep sound being emitted from the front speakers increases with decreasing distance. From a distance less than 30 cm (11.8 in), the sound becomes continuous.
The measuring range of the rear object sensors is between 30-250 cm (11.8-98.4 in). From a distance of 250 cm (98.4 in), the acoustic signal is active. The frequency of the beep sound being emitted from the rear speakers increases with decreasing distance. From a distance less than 30 cm (11.8 in), the sound becomes continuous.
The parking assist can be enabled and disabled by pressing the parking assist switch. When driving at speeds less than 8 km/h (5 MPH) or when engaging the reverse gear, the parking assist is activated. By subsequently pressing the parking assist switch the parking assist can be disabled again.
The front and rear parking assist control module carries out a self test and monitors the sensors for electrical and mechanical faults. Monitored is the power supply of each sensor and the sensor signals, which need to alter when the vehicle moves. If this is not the case, the sensor is acoustically blocked or faulty. Mud, ice and snow may cause obstruction of the function of the sensors. The front and rear parking assist control module also checks whether the correct type of sensor is installed. If any of these tests fails, a DTC with corresponding symptom is set, the parking assist is deactivated and a message is sent to the driver information center.