LIGHTING SYSTEM IG Signal Circuit

DESCRIPTION

This circuit detects the ignition switch ON or off condition, and sends it to the main body ECU (multiplex network body ECU).

WIRING DIAGRAM

A005GYME03

CAUTION / NOTICE / HINT

Tech Tips

Inspect the fuses for circuits related to this system before performing the following inspection procedure.

Note

Initialization is necessary when the main body ECU (multiplex network body ECU) is replaced* Click here.


  • *: w/ Automatic Light Control System

PROCEDURE


  1. READ VALUE USING INTELLIGENT TESTER (IG SW)


    1. Using the intelligent tester, read the Data List Click here.

      Main Body
      Tester Display Measurement Item/Range Normal Condition Diagnostic Note
      IG SW Ignition switch ON signal / ON or OFF

      ON: Ignition switch ON

      OFF: Ignition switch ACC or off

      		 -
      OK
      The display is as specified in the normal condition column.
      Result
      Result Proceed to
      NG A
      OK B

    B

    PROCEED TO NEXT SUSPECTED AREA SHOWN IN PROBLEM SYMPTOMS TABLE Click here

    A

  2. CHECK VEHICLE CONDITION


    1. Check the vehicle condition.

      Result
      Result Proceed to
      w/o Stop and Start System A
      w/ Stop and Start System B

    B

    CHECK HARNESS AND CONNECTOR (INSTRUMENT PANEL JUNCTION BLOCK - POWER SOURCE, BODY GROUND) Click here

    A

  3. CHECK HARNESS AND CONNECTOR (INSTRUMENT PANEL JUNCTION BLOCK - POWER SOURCE, BODY GROUND)


    1. Disconnect the 3A, 3B and 3E*1 or 3F*2 instrument panel junction block assembly connectors.


      • *1: for LHD

      • *2: for RHD

    2. Measure the voltage according to the value(s) in the table below.

      Standard Voltage
      for LHD
      Tester Connection Switch Condition Specified Condition
      3A-29 - Body ground Ignition switch ON 11 to 14 V
      3E-1 - Body ground Always 11 to 14 V
      for RHD
      Tester Connection Switch Condition Specified Condition
      3A-29 - Body ground Ignition switch ON 11 to 14 V
      3F-1 - Body ground Always 11 to 14 V

    3. Measure the resistance according to the value(s) in the table below.

      Standard Resistance (Check for Open)
      Tester Connection Condition Specified Condition
      3A-40 - 3A-54 Always Below 1 Ω
      3B-8 - Body ground Always Below 1 Ω
      Standard Resistance (Check for Short)
      Tester Connection Condition Specified Condition
      3A-54 - Body ground Always 10 kΩ or higher
      Result
      Result Proceed to
      NG A
      OK B

    A

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    B

    INSPECT INSTRUMENT PANEL JUNCTION BLOCK ASSEMBLY Click here

  4. CHECK HARNESS AND CONNECTOR (INSTRUMENT PANEL JUNCTION BLOCK - POWER SOURCE, BODY GROUND)


    1. Disconnect the 3A, 3B and 3E instrument panel junction block assembly connectors.

    2. Measure the voltage according to the value(s) in the table below.

      Standard Voltage
      Tester Connection Switch Condition Specified Condition
      3A-29 - Body ground Ignition switch ON 11 to 14 V
      3E-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
      3B-8 - Body ground Always Below 1 Ω

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    OK

  5. CHECK HARNESS AND CONNECTOR (ECO RUN VEHICLE CONVERTER - INSTRUMENT PANEL JUNCTION BLOCK)

    A005HW4E02
    Text in Illustration
    *a

    Component with harness connected

    (Instrument Panel Junction Block Assembly)

    1. Reconnect the 3A, 3B and 3E instrument panel junction block assembly connectors.

    2. Measure the voltage according to the value(s) in the table below.

      Standard Voltage
      Tester Connection Switch Condition Specified Condition
      3A-40 - Body ground Ignition switch ON 11 to 14 V

    NG

    GO TO STOP AND START SYSTEM Click here

    OK

  6. INSPECT INSTRUMENT PANEL JUNCTION BLOCK ASSEMBLY


    1. Remove the instrument panel junction block assembly Click here.

    2. Remove the main body ECU (multiplex network body ECU) from the instrument panel junction block assembly.

    3. Measure the resistance according to the value(s) in the table below.

      A005I1TE01
      Text in Illustration
      *A for LHD *B for RHD
      *a

      Component without harness connected

      (Instrument Panel Junction Block Assembly)

      		 - -
      Standard Resistance
      for LHD
      Tester Connection Condition Specified Condition
      3A-40 - MB-32 (IG) Always Below 1 Ω
      3E-1 - 3A-54

      Connect a positive (+) lead from the battery → 3A-29

      Connect a negative (-) lead from the battery → 3B-8

      		 Below 1 Ω

      Not connect a positive (+) lead from the battery → 3A-29

      Not connect a negative (-) lead from the battery → 3B-8

      		 10 kΩ or higher
      for RHD
      Tester Connection Condition Specified Condition
      3A-40 - MB-32 (IG) Always Below 1 Ω
      3F-1 - 3A-54

      Connect a positive (+) lead from the battery → 3A-29

      Connect a negative (-) lead from the battery → 3B-8

      		 Below 1 Ω

      Not connect a positive (+) lead from the battery → 3A-29

      Not connect a negative (-) lead from the battery → 3B-8

      		 10 kΩ or higher

    OK

    REPLACE MAIN BODY ECU (MULTIPLEX NETWORK BODY ECU) Click here

    NG

    REPLACE INSTRUMENT PANEL JUNCTION BLOCK ASSEMBLY Click here