AVC-LAN Circuit: Description

Each unit of the audio system connected to the AVC-LAN (communication bus) transfers the signal of each switch by communication.

When a short to +B or short to ground occurs in this AVC-LAN, the audio system will not function normally as the communication is discontinued.

1. INSPECT RADIO RECEIVER 
   1. Disconnect the radio receiver connectors.
   2. Measure the resistance according to the value(s) in RADIO RECEIVER  .

      Standard resistance 

      RADIO RECEIVER
      
      

      Tester Connection	Condition	Specified Condition
      ATX+ (R7-5) - ATX- (R7-15) ((1))	Always	60 to 80 Ω
      TXM+ (R8-9) - TXM- (R8-10)	Always	60 to 80 Ω
      (1) 10 Speaker System

      Fig 1: Inspecting Radio Receiver

      Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

   NG: REPLACE RADIO RECEIVER 

   OK: GO TO NEXT STEP 

2. CHECK HARNESS AND CONNECTOR 

   HINT:

   For details of the connectors, refer to the "TERMINALS OF ECU " .

   1. Referring to the AVC-LAN wiring diagram in Fig 2 , check all AVC-LAN circuits.
      1. Disconnect all connectors in all AVC-LAN circuits.
      2. Check for an open or short in all AVC-LAN circuits.

         OK: There is no open or short circuit. 

         Fig 2: AVC-LAN Wiring Diagram

         Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

   NG: REPAIR OR REPLACE HARNESS OR CONNECTOR 

   OK: PROCEED TO NEXT CIRCUIT INSPECTION SHOWN IN  PROBLEM SYMPTOMS TABLE