Navigation System: Description and Operation

NAVIGATION SYSTEM

Principles of Operation

Navigation System

The navigation system guides the user to a pre-entered destination. No navigation map DVD is needed, as the map guidance information is stored in the audio control module (ACM). The ACM calculates route information based on the global positioning system (GPS) data. The GPS antenna tracks several satellites simultaneously. The ACM also uses vehicle speed and transmission gear selected signals received through the medium speed controller area network (MS-CAN) to detect vehicle speed and direction, resulting in more accurate navigation tracking.
The navigation display is part of the ACM. Either the touchscreen or the buttons on the ACM can be used to interact with the navigation system.
The compass heading is derived from the GPS antenna signal. There are no serviceable parts for the compass.
A voice recognition system allows the user to interface with the system without using the touchscreen. A microphone located in the interior rear view mirror provides a direct input to the ACM.

Jukebox Feature

The ACM contains a 10 gigabyte on-board hard drive that is capable of storing music ripped (recorded) from a music disc. The music can be loaded into the jukebox by inserting a disc (in the correct format) and following the on-screen instructions to load the music into the ACM. The jukebox cannot rip MP3 discs.

Global Positioning System (GPS) Antenna

The GPS antenna receives information from satellite. The compass heading is also derived from the GPS signal. A combination GPS/satellite radio antenna is utilized.

Steering Wheel Controls

The steering wheel controls consist of a series of resistors. Each steering wheel control switch function corresponds with a specific resistance value within the switch. When a switch is pressed, the ACM monitors the change in reference voltage to determine the requested function.

Satellite Audio

The satellite audio system consists of the satellite radio receiver (integral to the ACM), a satellite radio antenna, and a satellite radio antenna cable. The satellite radio antenna receives digital audio signals and sends them to the ACM.

Network Communication

The following messages are utilized by the audio system for navigation-specific information: