Honda ACCORD HYBRID 2005 Service Manual page 2049

S y s t e m D e s c r i p t i o n
Overview
The navigation system is a highly-sophisticated, hybrid locating system that uses satellites and a map database to
s h o w y o u w h e r e you are and to help guide y o u to a desired destination.
The navigation system receives signals f r o m the global positioning system (GPS), a network of 24 satellites in orbit
around the earth. By receiving signals f r o m serveral of these satellites, the navigation system can determine the
latitude, longitude elevation of the vehicle. In addition, signals f r o m the system's y a w rate sensor and the PCM
(vehicle speed pulse) enable the system to keep track of the vehicle's direction and speed of travel.
This hybrid system has advantages over a system that is either entirely self-contained or one that relies totally on the
GPS. For example, the self-contained portion of the system can keep track of vehicle position even w h e n satellite
signals cannot be received. W h e n the navigation system is o n , the GPS can keep track of the vehicle position even
w h e n the vehicle is transported by ferry.
The navigation system applies all location, direction, and speed information to maps and calculates a route to the
destination entered. As y o u drive to that destination, the system provides both visual and audio guidance.
This navigation system also has voice recognition that allows voice control of most of the navigation functions. The
Talk and BACK buttons on the steering wheel activate the voice control. The voice control also allows control of the
audio and climate control.
The navigation system provides a trip computer function. The fuel e c o n o m y display is calculated by data provided by
the PCM. The PCM provides fuel pulses via the F-CAN bus, and a dedicated speed signal.
The illumination signal is used by the navigation unit to automatically switch the display between Night and Day
brightness modes w h e n Display is set to Auto. W h e n the instrument panel brightness control is set to full brightness,
the navigation system stays in the Day mode, even w i t h the headlights on. Display unit button i l l u m i n a t i o n is supplied
t h r o u g h the audio unit.
The GA-NET bus provides c o m m u n i c a t i o n between the navigation unit and the display unit. This bus also links the
components in the audio-HVAC display module. The bus is used to pass button and touch-screen c o m m a n d s to the
navigation unit. In addition, m u t i n g and voice control c o m m a n d s are sent to the display unit and the audio and climate
control systems for processing. The audio unit uses the bus to control the XM-receiver or other accessories.
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