Navigation Computer

The navigation computer is located in the luggage compartment, next to the battery.

The navigation computer incorporates the following:

• GPS receiver
• VICS receiver (market dependant)
• Traffic Message Channel (TMC) receiver

The navigation computer is connected to the MOST bus. The navigation computer generates its own graphics and transmits them to the TSD on a dedicated GVIF (Gigabyte video Interface) bus.

The navigation computer contains a solid state piezo gyro which measures the motion of the vehicle around its vertical axis. The gyro operates on the principle known as the Coriolis force. The Coriolis force is the force that appears to accelerate a body moving away from its rotational axis against the direction of rotation of the axis.

Using inputs from the ABS module, the GPS antenna and the gyro sensor, the computer calculates the vehicle's current position, direction and speed.

The navigation computer houses the DVD - ROM drive. The drive is used to read map data from region specific DVD's. The regions are as follows:

• Europe (3 discs)
• NAS (2 discs)
• Japan, Middle east and Australia (Idisc)

A button, located adjacent to the DVD slot, is provided to eject the DVD from the unit. Prior to ejecting the disc the slot protection has to be slid to the side. If the ignition is on, or the Entertainment System is in 1 - hour mode, one press of the button will eject the DVD.

The GPS receiver receives information from between 1 and 8 satellites at any one time. This information is received from the GPS antenna. The built in GPS receiver is used for calculating the position (i.e. Latitude, longitude and height), direction and speed.

The navigation computer uses non - volatile memory to store settings and configuration information when it is powered down. This process takes place just before the computer turns off.

The VICS system receiver allows the vehicle to receive information about traffic conditions from roadside transmitters and adjust the navigation instructions accordingly. The VICS receiver, receives information from the beacon antenna on the instrument panel and the FM antenna.

For additional information, refer to: Antenna (Description and Operation).

The TMC receiver decodes TMC data. The navigation computer then displays this information on the TSD and also re - routes the navigation guidance around any traffic hold ups. The TMC data is received from the FM (frequency modulation) antenna via the antenna signal splitter. For additional information, refer to: Antenna (Description and Operation).