as follows.
1. To solve sound problems, etc. caused by using components of different manufacturers
through signal standardization.
2. To allow each manufacturer to concentrate on developing products they do best. From this,
reasonably priced products can be produced.
HINT:
If a +B or GND short is detected in the AVC-LAN circuit, communication is interrupted and
the audio system will stop functioning.
If an audio system is equipped with a navigation system, the multi-display unit acts as the
master unit.
If the navigation system is not equipped, the audio head unit acts as the master unit instead. I
f
the radio and navigation assy is equipped, it is the master unit.
The radio receiver assy provides resistance to make communication possible.
The car audio system with an AVC-LAN circuit has a diagnostic function.
Each component has a specified number (3-digit) called a physical address. Each function
has a number (2-digit) called a logical address.
5.Communication system outline
a. Components of the navigation system communicate with each other via the AVC-LAN.
b. Radio receiver assy has enough resistance (60 to 80 ohms) necessary for transmitting the
communication. This is essential for communication.
c. If a short circuit or open circuit occurs in the AVC-LAN circuit, communication is interrupted and
the navigation system will stop functioning.
6.Diagnostic function outline
a. The audio system has a diagnostic function (the result is indicated on the master unit).
b. A 3-digit hexadecimal component code (physical address) is allocated to each component on the
AVC-LAN. Using this code, the component in the diagnostic function can be displayed.
7.Bluetooth outline
a. BLUETOOTH is a new wireless connection technology that uses the 2.4 GHz frequency band. This
makes it possible to connect a cellular phone (BLUETOOTH capable phone*1) to the multi-display
(BLUETOOTH system is built in), and use a hands-free function with the cellular phone in a
pocket or bag. As a result, it is not necessary to use a connector for the cellular phone.
*1: Some versions of BLUETOOTH capable cellular phone may not function.
HINT:
The communication performance of BLUETOOTH may vary depending on obstructions or radio
wave conditions between communication devices, electromagnetic radiation, communication
device sensitivit
y, or antenna capacity.
Fig. 10: Identifying Bluetooth Capable Cellular
Courtesy of TOYOTA MOTOR SALES, U.S.A., INC.
1.Vehicle brought into a workshop
2.Diagnostic questioning and symptom confirmation (see CUSTOMER PROBLEM ANALYSIS
CHECK )
Ask the customer about symptoms and confirm malfunctions. Fill out the Customer Problem Analysis
check sheet.
The screen displays nothing (go to step 6, proceed to "BLACK SCREEN (NO IMAGE APPEARS
ON NAVIGATION/AUDIO SCREEN)")
Other symptoms (go to step 3)
3.Confirm the system normal condition (see SYSTEM NORMAL CONDITION CHECK
)
Applicable (This is not a malfunction.)
Not applicable (go to step 4)
4.Check the diagnostic trouble codes (see DIAGNOSTIC TROUBLE CODE CHART
)
HINT:
If the system cannot enter the diagnosis mode, inspect each AVC-LAN communication signal and
