LIGHTING SYSTEM Taillight Relay Circuit

DESCRIPTION

The main body ECU (multiplex network body ECU) receives headlight dimmer switch information signals and illuminates the clearance lights*1, parking light*2, taillights and license plate lights.

*1: w/o Side Marker Light

*2: w/ Side Marker Light

WIRING DIAGRAM

A01QT1HE03
A01QP3FE02
A01QQ6KE02
A01QTWSE02
w/ Side Marker Light
*a License Plate Light Assembly LH
*b License Plate Light Assembly RH

CAUTION / NOTICE / HINT

Note


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

  • When replacing the main body ECU (multiplex network body ECU), make sure to replace it with a new one.

PROCEDURE


  1. PERFORM ACTIVE TEST USING GTS (TAILLIGHT RELAY)


    1. Using the GTS, perform the Active Test.

      Click here


      Body Electrical > Main Body > Active Test
      Tester Display Measurement Item Control Range Diagnostic Note
      Taillight Relay Taillight relay ON or OFF -

      Body Electrical > Main Body > Active Test
      Tester Display
      Taillight Relay
      Result
      Proceed to
      Taillights come on
      Taillights do not come on

    Taillights come on

    REPLACE MAIN BODY ECU (MULTIPLEX NETWORK BODY ECU) for LHD: REPLACE MAIN BODY ECU (MULTIPLEX NETWORK BODY ECU) Click here
    REPLACE MAIN BODY ECU (MULTIPLEX NETWORK BODY ECU) for RHD: REPLACE MAIN BODY ECU (MULTIPLEX NETWORK BODY ECU) Click here

    Taillights do not come on

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


    1. Disconnect the instrument panel junction block assembly connector.

    2. A01QQBZC01
      *a

      Front view of wire harness connector

      (to Instrument Panel Junction Block Assembly)

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

      Standard Voltage
      Tester Connection Condition Specified Condition
      3A-1 - Body ground Always 11 to 14 V
      Result
      Proceed to
      OK
      NG

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    OK

  3. INSPECT INSTRUMENT PANEL JUNCTION BLOCK ASSEMBLY (TAIL RELAY)


    1. A01QTIQN02

      w/o Side Marker Light:


      1. Remove the instrument panel junction block assembly.

        for LHD:

        Click here

        for RHD:

        Click here

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

        for LHD:

        Click here

        for RHD:

        Click here

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

        Standard Resistance
        Tester Connection Condition Specified Condition
        3A-1 - 3B-28 Battery voltage applied between terminals 3A-1 and A-14 (TRLY) Below 1 Ω
        Battery voltage not applied between terminals 3A-1 and A-14 (TRLY) 10 kΩ or higher
        3A-1 - 3E-38 Battery voltage applied between terminals 3A-1 and A-14 (TRLY) Below 1 Ω
        Battery voltage not applied between terminals 3A-1 and A-14 (TRLY) 10 kΩ or higher
    2. A01QRY4E01

      w/ Side Marker Light


      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.

        Standard Resistance
        Tester Connection Condition Specified Condition
        3A-1 - 3B-48 Battery voltage applied between terminals 3A-1 and A-14 (TRLY) Below 1 Ω
        Battery voltage not applied between terminals 3A-1 and A-14 (TRLY) 10 kΩ or higher
        3A-1 - 3B-27 Battery voltage applied between terminals 3A-1 and A-14 (TRLY) Below 1 Ω
        Battery voltage not applied between terminals 3A-1 and A-14 (TRLY) 10 kΩ or higher
        3A-1 - 3B-28 Battery voltage applied between terminals 3A-1 and A-14 (TRLY) Below 1 Ω
        Battery voltage not applied between terminals 3A-1 and A-14 (TRLY) 10 kΩ or higher
        3A-1 - 3C-20 Battery voltage applied between terminals 3A-1 and A-14 (TRLY) Below 1 Ω
        Battery voltage not applied between terminals 3A-1 and A-14 (TRLY) 10 kΩ or higher
        3A-1 - 3E-37 Battery voltage applied between terminals 3A-1 and A-14 (TRLY) Below 1 Ω
        Battery voltage not applied between terminals 3A-1 and A-14 (TRLY) 10 kΩ or higher
        3A-1 - 3E-38 Battery voltage applied between terminals 3A-1 and A-14 (TRLY) Below 1 Ω
        Battery voltage not applied between terminals 3A-1 and A-14 (TRLY) 10 kΩ or higher
      Result
      Proceed to
      OK
      NG

    OK

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

    NG

    REPLACE INSTRUMENT PANEL JUNCTION BLOCK ASSEMBLY for LHD: REPLACE INSTRUMENT PANEL JUNCTION BLOCK ASSEMBLY Click here
    REPLACE INSTRUMENT PANEL JUNCTION BLOCK ASSEMBLY for RHD: REPLACE INSTRUMENT PANEL JUNCTION BLOCK ASSEMBLY Click here