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IG Signal Circuit: Procedure

WARNING: This page is about a different variant/trim than selected.
  1. READ VALUE USING TECHSTREAM 
    1. Connect the Techstream to the DLC3.
    2. Turn the power switch on (IG).
    3. Turn the Techstream on.
    4. Enter the following menus: Body Electrical / Main Body / Data List.
    5. Read the display on the Techstream.
      MAIN BODY

      Tester Display Measurement Item/Range Normal Condition Diagnostic Note
      IG SW Power switch IG signal/ON or OFF ON: Power switch on (IG)
      OFF: Power switch off      		 -

      OK

      Normal conditions listed above are displayed.

    NG → See step   2 

    OK → See step   5 

  2. CHECK HARNESS AND CONNECTOR (INSTRUMENT PANEL JUNCTION BLOCK - BATTERY AND BODY GROUND) 
    1. Disconnect the 2E and 2B instrument panel junction block assembly connectors.
    2. Measure the voltage according to the value(s) in the table below.

      Standard Voltage

      Tester Connection Condition Specified Condition
      2E-1 - Body ground Always 11 to 14 V
    3. Measure the resistance according to the value(s) in the table below.

      Standard Resistance

      Tester Connection Condition Specified Condition
      2B-6 - Body ground Always Below 1 Ω

    NG → REPAIR OR REPLACE HARNESS OR CONNECTOR 

    OK: Go to next step 

  3. CHECK HARNESS AND CONNECTOR (IG POWER SOURCE CIRCUIT) 
    1. Measure the voltage according to the value(s) in the table below.
      Fig 1: Identifying 2B Connector
      GTY235067Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

      Standard Voltage

      Tester Connection Condition Specified Condition
      2B-25 - Body ground Power switch on (IG) 11 to 14 V
      TEXT IN ILLUSTRATION

      *1 Front view of wire harness connector
      (to Instrument Panel Junction Block Assembly)

    NG → REPAIR OR REPLACE HARNESS OR CONNECTOR 

    OK: Go to next step 

  4. INSPECT INSTRUMENT PANEL JUNCTION BLOCK ASSEMBLY 
    1. Remove the main body ECU (multiplex network body ECU) from the instrument panel junction block assembly.
      Fig 2: Identifying Instrument Panel Junction Block Assembly
      GTY229740Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
    2. Reconnect the instrument panel junction block assembly connectors.
    3. Measure the voltage according to the value(s) in the table below.

      Standard Voltage

      Tester Connection Condition Specified Condition
      A-32 (IG) - Body ground Power switch on (IG) 11 to 14 V
      TEXT IN ILLUSTRATION

      *1 Instrument Panel Junction Block Assembly

    NG → REPLACE INSTRUMENT PANEL JUNCTION BLOCK ASSEMBLY 

    OK → See step   6 

  5. PROCEED TO NEXT SUSPECTED AREA SHOWN IN PROBLEM SYMPTOMS TABLE. Refer to  PROBLEM SYMPTOMS TABLE  
  6. REPLACE MAIN BODY ECU (MULTIPLEX NETWORK BODY ECU). Refer to  COMPONENTS 
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