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Home >> Lexus >> 2002 >> ES 300 >> Repair and Diagnosis >> External Pages >> Different car >> Section 306 (LEXUS Navigation System - Diagnosis) >> Map Disc Cannot Be Inserted >> Inspection Procedure
July 1: So it begins. Don't worry, this is not in the correct legal jurisdiction!

Inspection Procedure

WARNING: This page is about a different car, the 2003 Lexus ES 300. However, it is still accessible from the selected car via links, so may be relevant.
  1. INSPECT NAVIGATION ECU (+B, ACC, GND) 
    1. Remove the navigation ECU with connectors with still connected.
    2. Check voltage.
      1. Measure voltage between terminals +B, ACC and GND of navigation ECU at each conditions, as shown in the chart.

        Standard: 

        TERMINAL STANDARD VOLTAGE

        Terminal Condition Voltage (v)
        +B <=> GND Constant 10-14V
        ACC <=> GND Turn ignition switch ACC 10-14V
        Fig 1: Inspecting Navigation ECU (+B, ACC, GND)
        G03372715Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
    3. Check continuity.
      1. Check that the continuity exists between terminal GND of navigation ECU and body ground.

        Standard: Continuity exists. 

    1. NG: REPAIR OR REPLACE HARNESS OR CONNECTOR 
    2. OK: CHECK AND REPLACE NAVIGATION ECU