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Inspection Procedure

WARNING: This page is about a different car, the 2005 Lexus LX 470. However, it is still accessible from the selected car via links, so may be relevant.
  1. Check voltage between terminals +B1, ACC and GND of navigation ECU. 
    1. Disconnect the connector from the navigation ECU.
    2. Measure the voltage according to the value(s) in the table below.

      Standard: 

      TESTER CONNECTION SPECIFIED CONDITION

      Tester connection Condition Specified condition
      +B1 - GND Always 10 to 14 V
      ACC - GND Ignition SW ACC 10 to 14 V
    Fig 1: Locating Terminals +B1, ACC and GND
    G02988034Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
    1. OK: Proceed to next circuit inspection shown in problem symptoms table. (See  PROBLEM SYMPTOMS TABLE   ) 
    2. NG: Go To Next Step. 
  2. Check continuity between terminal GND of navigation ECU and body ground. 
    1. Disconnect the connector from the navigation ECU.
    2. Measure the resistance according to the value(s) in the table below.

      Standard: 

      TESTER CONNECTION SPECIFIED CONDITION

      Tester connection Condition Specified condition
      GND - Body ground Always Below 1 Ω
    Fig 2: Locating Terminal GND
    G02988035Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
    1. OK: Repair or replace harness or connector between navigation ECU and fuse. 
    2. NG: Repair or replace harness or connector between navigation ECU and body ground. 
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