Principles of Operation

PRINCIPLES OF OPERATION

Navigation System
The navigation module controls the operation and the interface between the user, the vehicle subsystems, and the external components. The navigation module is on the standard corporate protocol (SCP) network and can be diagnosed with a diagnostic tool. Communication through the controller area network (CAN) uses data transmitted and received between the navigation module and the audio unit to control the video screen display through the video interface circuits.

The vehicle navigation system guides the user to a pre-entered destination. A map digital versatile disc (DVD) stored in the navigation module sends route calculation data to the audio unit. The audio unit audibly and visually instructs the user of the maneuvers required to arrive at the destination entered.

A voice recognition system allows the user to interface with the system without using the touch screen. A microphone located in the rear view mirror provides a direct input to the navigation module.

The navigation module uses the global positioning system (GPS) antenna, vehicle speed, and other internal sensor information to accurately establish vehicle position. In order to calculate the initial vehicle position, the GPS antenna is used to track several available satellites simultaneously. The GPS antenna only receives data and does not communicate with the satellites. A gyroscope integral to the navigation module monitors the pitch and yaw of the vehicle created during cornering or turning. A hardwired vehicle speed input from the anti-lock brake system (ABS) module and a reverse input from the digital transmission range (TR) sensor through the SCP network are also used to detect vehicle speed and direction changes.