Description of On-Board Diagnostics

Wiring Diagram:

DIAGNOSIS SYSTEM DESCRIPTION

HINT: There are several diagnosis functions in the LEXUS Navigation System.

Though each operation procedure is explained, the outline is as follows.

a. SYSTEM CHECK
In this mode, communication circuit is inspected and self diagnosis is conduced in each system (Navigation ECU, display ECU, radio receiver, power amplifier and CD auto changer). The result is displayed on the screen. At the bottom of the screen the map area is displayed.

b. DISPLAY CHECK
In this mode, images and touch switches on the screen are inspected.

c. VEHICLE SIGNAL DISPLAY CHECK
In this mode, 2 items of vehicle signal conditions input in the navigation ECU are displayed at the real time (renewed every approx. 1 sec.).

d. INTERNAL COEFFICIENT SET
This sets time and data of calendar and compensation coefficient to improve the accuracy of navigation system. It is not always necessary to adjust the compensation Coefficient, however when the error is excessive due to replacement of tires etc., reset the coefficient again.

e. DIAGNOSIS MEMORY
Information is stored in the diagnosis memory when an error occurs in the communication of the system and the system.

f. GPS INFORMATION
GPS information receiving condition is displayed.

g. TONE QUALITY CHECK
Chime or navigation voice recorded in HARD DISK can be heard when necessary.

h. DISK INFORMATION
Area and version No. of map data base and version No. of navigation soft are displayed.