Component Tests and General Diagnostics

CIRCUIT DESCRIPTION
Each unit of LEXUS navigation system connected with AVC-LAN (communication bus) transfers the signal of each switch by communication.

In the case that this AVC-LAN has +B short and GND, LEXUS navigation system will not function normally as the communication is discontinued.

In this AVC-LAN, Navigation ECU, becomes the master of the communication, and the audio head unit has a resistance necessary for transmitting the communication.

Display ECU is connected between them, It has the structure that makes communication impossible without Navigation ECU, Display ECU or Audio head unit.

AVC - LAN:

Wiring Diagram:

Step 1:

Steps 2 - 4:

Steps 5 - 7:

Step 8:

INSPECTION PROCEDURE