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Home >> Toyota >> 2004 >> Matrix Base, FWD, Standard >> Repair and Diagnosis >> External Pages >> Different car >> Section 778 (LEXUS Navigation System - Diagnosis) >> Circuit Inspection >> AVC-LAN (Communication Bus Circuit) >> Inspection Procedure
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Inspection Procedure

WARNING: This page is about a different car, the 2004 Lexus IS 300. However, it is still accessible from the selected car via links, so may be relevant.
  1. Disconnect the connector "S7" of stereo component amplifier and check if AVC-LAN will be recovered normally 

    CHECK: 

    Check that the display will change by pressing either of the Panel switch or touch switch on the display

    HINT:

    It can be judged that AVC-LAN is recovered if the display is changed

    1. OK: Replace the power amplifier. 
    2. NG: Go to next step. 
  2. Check wire harness and connector between radio and player and stereo component amplifier (See  HOW TO USE THE DIAGNOSTIC CHART AND INSPECTION PROCEDURE  ) 
    1. NG: Repair or replace wire harness or connector 
    2. OK: Go to next step. 
  3. Check wire harness and connector between multi display and stereo component amplifier (See  HOW TO USE THE DIAGNOSTIC CHART AND INSPECTION PROCEDURE  ) 
    1. NG: Repair or replace wire harness or connector 
    2. OK: Go to next step. 
  4. Check wire harness and connector between multi display and navigation ECU. (See  HOW TO USE THE DIAGNOSTIC CHART AND INSPECTION PROCEDURE  ) 
    1. NG: Repair or replace wire harness or connector 
    2. OK: Go to next step. 
  5. Skip Display ECU and Check AVC-LAN 

    PREPARATION: 

    1. Connect all the connectors except "N4" of the navigation ECU
    2. Using 2 SSTs (Diagnosis check wire P/N 09893-12040) connect the terminal TX-1 and TX1+ of connector "N4" of navigation ECU
      Fig 1: Checking Navigation ECU
      G01497382Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

    CHECK: 

    Operate radio and player (CD, Cassette tape, etc,) and check that the sound comes out form the speaker (check that AVC-LAN is recovered)

    1. OK: Replace the navigation ECU 
    2. NG: Go to next step. 
  6. Skip multi display and check AVC-LAN 

    PREPARATION: 

    • Connect the navigation ECU connector
    • Disconnect the connector "M4" of the multi display
    • Using 2 SSTs (Diagnosis check wire P/N 09893-12040) connect the terminal GTX- and GTX1+ of connector "M4" of multi display
      Fig 2: Identifying Multi Display (1 Of 2)
      G01497383Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

      CHECK: 

      Operate radio and player (CD, Cassette tape, etc,) and check that the sound comes out form the speaker

    1. OK Replace the multi display 
    2. NG: Go to next step. 
  7. Skip radio and player and check AVC-LAN 

    PREPARATION: 

    • Connect multi display connector
    • Disconnect radio and player "R2" connector
    • Using SST (Navigation Check wire P/N 09843-18050) connect the terminal T+ to terminal TX- of "R2" connector of radio and player
      Fig 3: Identifying Multi Display (2 Of 2)
      G01497384Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

    CHECK: 

    Operate the panel switch and the tough switch of the display and check that the navigation functions

    (Check that AVC-LAN is recovered)

    1. OK Replace the radio and player 
    2. NG: Go to next step. 

      Replace the stereo component amplifier 

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