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


  1. A0029HKE02

CAUTION / NOTICE / HINT

Note


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

  • If the main body ECU (multiplex network body ECU) is replaced, refer to Service Bulletin.*1

  • As the door control battery is installed between the vehicle battery and main body ECU (multiplex network body ECU), first perform the inspections in On-Vehicle Inspection to confirm that there are no malfunctions in the power source circuit for the main body ECU (multiplex network body ECU) before performing this troubleshooting procedure.*2

    Click here


  • *1: w/ Smart Entry and Start System

  • *2: for LHD

PROCEDURE


  1. CONFIRM MODEL


    1. Choose the model to be inspected.

      Result
      Result Proceed to
      w/ Smart Entry and Start System A
      w/o Smart Entry and Start System B

    B

    READ VALUE USING GTS Click here

    A

  2. CHECK FOR DTC (SMART ENTRY AND START SYSTEM (for Start Function))


    1. Clear the DTCs.

      Click here


      Body Electrical > Entry&Start > Clear DTCs

    2. Check for DTCs.

      Click here


      Body Electrical > Entry&Start > Trouble Codes
      Result
      Result Proceed to
      Smart Entry and Start System (for Start Function) DTCs are not output A
      Smart Entry and Start System (for Start Function) DTCs are output B

    B

    GO TO SMART ENTRY AND START SYSTEM (for Start Function) Click here

    A

  3. READ VALUE USING GTS


    1. Connect the GTS to the DLC3.

    2. Turn the ignition switch to ON.

    3. Turn the GTS on.

    4. Enter the following menus: Body Electrical / Main Body / Data List.

    5. Read the Data List according to the display on the GTS.


      Body Electrical > Main Body > Data List
      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 off

      		 "OFF" is also displayed for this item when the ignition switch is ACC.

      Body Electrical > Main Body > Data List
      Tester Display
      IG SW
      OK
      Normal conditions listed above are displayed.
      Result
      Proceed to
      OK
      NG

    OK

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

    NG

  4. CHECK HARNESS AND CONNECTOR (BATTERY POWER SOURCE)


    1. Disconnect the 4K instrument panel junction block assembly connector.

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

      Standard Voltage
      Tester Connection Condition Specified Condition
      4K-1 - Body ground Always 11 to 14 V
      Result
      Proceed to
      OK
      NG

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    OK

  5. CHECK HARNESS AND CONNECTOR (INSTRUMENT PANEL JUNCTION BLOCK ASSEMBLY - INSTRUMENT PANEL JUNCTION BLOCK ASSEMBLY)


    1. Disconnect the 4F instrument panel junction block assembly connector.

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      4F-19 - 4F-24 Always Below 1 Ω
      4F-19 or 4F-24 - Body ground Always 10 kΩ or higher
      Result
      Proceed to
      OK
      NG

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    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.

      Click here

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

      A0027ZTC01
      *a

      Component without harness connected

      (Instrument Panel Junction Block Assembly)

      		 - -
      Standard Resistance
      Tester Connection Condition Specified Condition
      4K-1 - 4F-19 Battery not connected to 4A-16 and 4A-27 10 kΩ or higher
      4K-1 - 4F-19

      Battery positive (+) → 4A-16

      Battery negative (-) → 4A-27

      		 Below 1 Ω
      4F-24 - MB-32 (IG) Always Below 1 Ω
      Result
      Proceed to
      OK
      NG

    OK

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

    NG

    REPLACE INSTRUMENT PANEL JUNCTION BLOCK ASSEMBLY Click here

  7. READ VALUE USING GTS


    1. Connect the GTS to the DLC3.

    2. Turn the ignition switch to ON.

    3. Turn the GTS on.

    4. Enter the following menus: Body Electrical / Main Body / Data List.

    5. Read the Data List according to the display on the GTS.


      Body Electrical > Main Body > Data List
      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 off

      		 "OFF" is also displayed for this item when the ignition switch is ACC.

      Body Electrical > Main Body > Data List
      Tester Display
      IG SW
      OK
      Normal conditions listed above are displayed.
      Result
      Proceed to
      OK
      NG

    OK

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

    NG

  8. CHECK HARNESS AND CONNECTOR (INSTRUMENT PANEL JUNCTION BLOCK ASSEMBLY - IG1 NO. 3 RELAY POWER SOURCE AND BODY GROUND)


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

      Standard Voltage
      Tester Connection Condition Specified Condition
      4A-16 - Body ground Ignition switch ON 11 to 14 V

    2. Disconnect the 4A instrument panel junction block assembly connectors.

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      4A-27 - Body ground Always Below 1 Ω
      Result
      Proceed to
      OK
      NG

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    OK

  9. CHECK HARNESS AND CONNECTOR (BATTERY POWER SOURCE)


    1. Disconnect the 4K 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
      4K-1 - Body ground Always 11 to 14 V
      Result
      Proceed to
      OK
      NG

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    OK

  10. CHECK HARNESS AND CONNECTOR (INSTRUMENT PANEL JUNCTION BLOCK ASSEMBLY - INSTRUMENT PANEL JUNCTION BLOCK ASSEMBLY)


    1. Disconnect the 4F instrument panel junction block assembly connector.

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      4F-19 - 4F-24 Always Below 1 Ω
      4F-19 or 4F-24 - Body ground Always 10 kΩ or higher
      Result
      Proceed to
      OK
      NG

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    OK

  11. 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.

      Click here

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

      A0027ZTC01
      *a

      Component without harness connected

      (Instrument Panel Junction Block Assembly)

      		 - -
      Standard Resistance
      Tester Connection Condition Specified Condition
      4K-1 - 4F-19 Battery not connected to 4A-16 and 4A-27 10 kΩ or higher
      4K-1 - 4F-19

      Battery positive (+) → 4A-16

      Battery negative (-) → 4A-27

      		 Below 1 Ω
      4F-24 - MB-32 (IG) Always Below 1 Ω
      Result
      Proceed to
      OK
      NG

    OK

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

    NG

    REPLACE INSTRUMENT PANEL JUNCTION BLOCK ASSEMBLY Click here