Circuit Description
WARNING: This page is about a different car, the 2005 Lexus RX 330. However, it is still accessible from the selected car via links, so may be relevant.
Each unit of the LEXUS navigation system connected to the AVC-LAN (communication bus) communicates by transferring the signals from each switch.
When a short to +B or short to ground occurs in this AVC-LAN, the LEXUS navigation system will not function normally as communication is discontinued.
In this AVC-LAN, the multi-display becomes the communication master, and the radio receiver assy has enough resistance necessary for transmitting the communication.
The LEXUS navigation system has the structure that makes communication impossible without the navigation ECU, multi-display or radio receiver assy.