LIGHTING SYSTEM Headlight Dimmer Switch Circuit

DESCRIPTION

The main body ECU (multiplex network body ECU) receives the following switch information:


WIRING DIAGRAM


  1. for LHD

    A00289RE17

  2. for RHD

    A002911E14

CAUTION / NOTICE / HINT

Note


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


    • *: w/ Smart Entry and Start System

  • 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.*

    Click here


    • *: for LHD

PROCEDURE


  1. 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 display on the GTS.


      Body Electrical > Main Body > Data List
      Tester Display Measurement Item Range Normal Condition Diagnostic Note
      Dimmer SW Dimmer switch high position signal ON or OFF

      ON: Dimmer switch in high or high flash position

      OFF: Dimmer switch in low position

      		 -
      Passing Light SW Dimmer switch high flash position (pass) signal ON or OFF

      ON: Dimmer switch in high flash position

      OFF: Dimmer switch not in high flash position

      		 -
      Rear Fog Light SW Fog light switch rear position ON or OFF

      ON: Fog light switch in rear position

      OFF: Fog light switch off

      		 *
      Front Fog Light SW Fog light switch front position signal ON or OFF

      ON: Fog light switch in front position

      OFF: Fog light switch off

      		 -
      Auto Light SW Light control switch AUTO position signal ON or OFF

      ON: Light control switch in AUTO position

      OFF: Light control switch not in AUTO position

      		 -
      Head Light SW (Head) Light control switch head position signal ON or OFF

      ON: Light control switch in head position

      OFF: Light control switch not in head position

      		 -
      Head Light SW (Tail) Light control switch tail position signal ON or OFF

      ON: Light control switch in tail or head position

      OFF: Light control switch in neither tail nor head position

      		 -

      • *: w/ Rear Fog Light


      Body Electrical > Main Body > Data List
      Tester Display
      Dimmer SW
      Passing Light SW
      Rear Fog Light SW
      Front Fog Light SW
      Auto Light SW
      Head Light SW (Head)
      Head Light SW (Tail)
      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

  2. INSPECT HEADLIGHT DIMMER SWITCH ASSEMBLY

    Tech Tips

    Inspect the items that did not change as a result of monitoring the Data List.


    1. Remove the headlight dimmer switch assembly.

      Click here

    2. for LHD:


      1. A0029HIC73
        *A w/ Rear Fog Light
        *a

        Component without harness connected

        (Headlight Dimmer Switch Assembly)

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

        Standard Resistance
        Light Control Switch
        Tester Connection Condition Specified Condition
        18 (T) - 15 (EL) Light control switch off 10 kΩ or higher
        19 (H) - 15 (EL) 10 kΩ or higher
        20 (A) - 15 (EL) 10 kΩ or higher
        19 (H) - 18 (T) 10 kΩ or higher
        20 (A) - 18 (T) 10 kΩ or higher
        19 (H) - 20 (A) 10 kΩ or higher
        18 (T) - 15 (EL) Light control switch in tail position Below 1 Ω
        18 (T) - 15 (EL) Light control switch in head position Below 1 Ω
        19 (H) - 15 (EL) Below 1 Ω
        18 (T) - 19 (H) Below 1 Ω
        20 (A) - 15 (EL) Light control switch in AUTO position Below 1 Ω
        Dimmer Switch
        Tester Connection Condition Specified Condition
        16 (HL) - 15 (EL) Dimmer switch in low position Below 1 Ω
        14 (HU) - 15 (EL) Dimmer switch in high position Below 1 Ω
        14 (HU) - 15 (EL) Dimmer switch in high flash position Below 1 Ω
        17 (HF) - 15 (EL) Below 1 Ω
        14 (HU) - 17 (HF) Below 1 Ω
        Fog Light Switch
        Tester Connection Condition Specified Condition
        9 (BFG) - 8 (LFG) Fog light switch off 10 kΩ or higher
        7 (B) - 8 (LFG)* 10 kΩ or higher
        7 (B) - 9 (BFG) 10 kΩ or higher
        9 (BFG) - 8 (LFG) Fog light switch in front position Below 1 Ω
        7 (B) - 8 (LFG)* Fog light switch in rear position Below 1 Ω
        9 (BFG) - 8 (LFG)* Below 1 Ω
        9 (BFG) - 7 (B)* Below 1 Ω

        • *: w/ Rear Fog Light

    3. for RHD:


      1. A0029HIC76
        *a

        Component without harness connected

        (Headlight Dimmer Switch Assembly)

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

        Standard Resistance
        Light Control Switch
        Tester Connection Condition Specified Condition
        13 (T) - 16 (EL) Light control switch off 10 kΩ or higher
        12 (H) - 16 (EL) 10 kΩ or higher
        11 (A) - 16 (EL) 10 kΩ or higher
        11 (A) - 12 (H) 10 kΩ or higher
        11 (A) - 13 (T) 10 kΩ or higher
        12 (H) - 13 (T) 10 kΩ or higher
        13 (T) - 16 (EL) Light control switch in tail position Below 1 Ω
        13 (T) - 16 (EL) Light control switch in head position Below 1 Ω
        12 (H) - 16 (EL) Below 1 Ω
        12 (H) - 13 (T) Below 1 Ω
        11 (A) - 16 (EL) Light control switch in AUTO position Below 1 Ω
        Dimmer Switch
        Tester Connection Condition Specified Condition
        15 (HL) - 16 (EL) Dimmer switch in low position Below 1 Ω
        17 (HU) - 16 (EL) Dimmer switch in high position Below 1 Ω
        17 (HU) - 16 (EL) Dimmer switch in high flash position Below 1 Ω
        14 (HF) - 16 (EL) Below 1 Ω
        14 (HF) - 17 (HU) Below 1 Ω
        Fog Light Switch
        Tester Connection Condition Specified Condition
        2 (BFG) - 3 (LFG) Fog light switch off 10 kΩ or higher
        2 (BFG) - 3 (LFG) Fog light switch in front position Below 1 Ω
      Result
      Proceed to
      OK
      NG

    NG

    REPLACE HEADLIGHT DIMMER SWITCH ASSEMBLY Click here

    OK

  3. CHECK HARNESS AND CONNECTOR (HEADLIGHT DIMMER SWITCH ASSEMBLY - MAIN BODY ECU (MULTIPLEX NETWORK BODY ECU))


    1. Disconnect the F19 main body ECU (multiplex network body ECU) connector.

    2. for LHD:


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

        Standard Resistance
        Tester Connection Condition Specified Condition
        F59-14 (HU) - F19-24 (HU) Always Below 1 Ω
        F59-17 (HF) - F19-10 (HF) Always Below 1 Ω
        F59-18 (T) - F19-22 (TAIL) Always Below 1 Ω
        F59-19 (H) - F19-12 (HEAD) Always Below 1 Ω
        F59-20 (A) - F19-8 (A) Always Below 1 Ω
        F59-9 (BFG) - F19-26 (FFOG) Always Below 1 Ω
        F59-7 (B) - F19-23 (RFOG)* Always Below 1 Ω
        F59-14 (HU) - Body ground Always 10 kΩ or higher
        F59-17 (HF) - Body ground Always 10 kΩ or higher
        F59-18 (T) - Body ground Always 10 kΩ or higher
        F59-19 (H) - Body ground Always 10 kΩ or higher
        F59-20 (A) - Body ground Always 10 kΩ or higher
        F59-9 (BFG) - Body ground Always 10 kΩ or higher
        F59-7 (B) - Body ground*1 Always 10 kΩ or higher
        F59-15 (EL) - Body ground Always Below 1 Ω
        F59-8 (LFG) - Body ground Always Below 1 Ω

        • *: w/ Rear Fog Light

    3. for RHD:


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

        Standard Resistance
        Tester Connection Condition Specified Condition
        F60-17 (HU) - F19-24 (HU) Always Below 1 Ω
        F60-14 (HF) - F19-10 (HF) Always Below 1 Ω
        F60-13 (T) - F19-22 (TAIL) Always Below 1 Ω
        F60-12 (H) - F19-12 (HEAD) Always Below 1 Ω
        F60-11 (A) - F19-8 (A) Always Below 1 Ω
        F60-2 (BFG) - F19-26 (FFOG) Always Below 1 Ω
        F60-17 (HU) - Body ground Always 10 kΩ or higher
        F60-14 (HF) - Body ground Always 10 kΩ or higher
        F60-13 (T) - Body ground Always 10 kΩ or higher
        F60-12 (H) - Body ground Always 10 kΩ or higher
        F60-11 (A) - Body ground Always 10 kΩ or higher
        F60-2 (BFG) - Body ground Always 10 kΩ or higher
        F60-16 (EL) - Body ground Always Below 1 Ω
        F60-3 (LFG) - Body ground Always Below 1 Ω
      Result
      Proceed to
      OK
      NG

    OK

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

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR