Global Positioning System

The navigation system receives GPS information via the GPS antenna. The GPS signals are used by the navigation system to calculate the vehicle's position. Once the driver has input a desired destination, the navigation system can calculate a route, based on the driver's pre-determined preferences or the default settings in the navigation system.

The navigation system is accessed from the TS (Touch Screen) home menu.

Navigation is initiated by the driver inputting a destination. This can be achieved by:

• Entering an address using the TS
• Entering a post code
• Choosing a previous destination
• Choosing a point of interest from the map disc database
• Choosing the home location
• Choosing a memory stored location

The driver is then guided to the destination by a scrolling map display and voice guidance. The display can be varied by scale and display type.

Selection of 'Navigation' on the TS home menu and subsequent submenu selection sends a control request signal to the navigation computer on the MOST (Media Oriented System Transport) ring Rest of World/Japan only. The requested control information is processed by the IAM for ROW; or the dedicated navigation computer for Japan and Asia.

• On ROW vehicles, if voice guidance is operational, the voice signals are passed from the IAM to the AAM on the MOST ring for output on the speaker system.
• On Japan vehicles, if voice guidance is operational, the voice signal information is relayed from the navigation computer on the MOST to the AAM for output on the speaker system.

The navigation audio output is through the front speakers while the background audio, for example radio or CD (compact disc), is played at a reduced volume on the rear speakers. On Asia vehicles the radio or CD output is muted while the navigation audio output is transmitted.

The GPS signal is available to the navigation system at all times when the vehicle ignition is switched on.

Navigation voice commands are made using the voice recognition system. The TS processes the analogue signal from the voice recognition switch. This is passed from the TS onto the MOST system to the voice recognition control software which is integral with the IAM (ROW) or navigation computer (Japan). Voice control of the navigation system is not available on Asia specification vehicles.

The TS sends an instruction via the MOST ring to the IAM to turn on the microphone facility. The microphone is hardwired to the IAM. For the ROW system, spoken voice commands are processed by the IAM. The processed commands are then sent to the TS to determine which control signals need to be sent to the navigation system.

For the Japan system, the analogue voice signals are relayed from the IAM via the MOST ring directly to the navigation computer (for processing). Navigation commands are handled internally within the navigation computer without the need for communicating with the TS for control.