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Inspection Procedure

WARNING: This page is about a different car, the 2008 Toyota Avalon. However, it is still accessible from the selected car via links, so may be relevant.
  1. INSPECT NAVIGATION ECU 
    1. Measure the voltage according to the value(s) in the table below.

      Standard voltage 

      TESTER CONNECTION SPECIFIED CONDITION CHART

      Tester connection Condition Specified condition
      MACC - Body ground Ignition switch on (ACC) 4 to 6 V

    NG: REPLACE NAVIGATION ECU 

    Fig 1: Inspecting Navigation ECU
    G05408007Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

    OK: Go to Next Step 

  2. CHECK HARNESS AND CONNECTOR (NAVIGATION ECU - BODY GROUND) 
    1. Disconnect the navigation ECU connector L18.
    2. Measure the resistance according to the value(s) in the table below.

      Standard resistance 

      TESTER CONNECTION SPECIFIED CONDITION CHART

      Tester connection Condition Specified condition
      SNSE - Body ground Always Below 1 Ω

    NG: REPAIR OR REPLACE HARNESS OR CONNECTOR 

    Fig 2: Disconnecting Navigation ECU Connector L18
    G05408008Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

    OK: Go to Next Step 

  3. CHECK HARNESS AND CONNECTOR (OVERHEAD J/B - NAVIGATION ECU) 
    1. Disconnect the overhead J/B connector N5 and navigation ECU connector L18.
    2. Measure the resistance according to the value(s) in the table below.

      Standard resistance 

      TESTER CONNECTION SPECIFIED CONDITION CHART

      Tester connection Condition Specified condition
      MACC - ACC Always Below 1 Ω
      MIC+ - MI1+ Always Below 1 Ω
      MIC- - MIC- Always Below 1 Ω
      MACC - Body ground Always 10 kΩ or higher
      MIC+ - Body ground Always 10 kΩ or higher
      MIC- - Body ground Always 10 kΩ or higher

    NG: REPAIR OR REPLACE HARNESS OR CONNECTOR 

    Fig 3: Checking Harness And Connector (Overhead J/B - Navigation ECU)
    G05006471Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

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