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

    B0019BTE06

  2. for RHD

    B0019BTE07

CAUTION / NOTICE / HINT

Note


  • w/ Door Control Battery:

    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.

  • Recognition code registration is necessary when replacing the main body ECU (multiplex network body ECU).

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

PROCEDURE


  1. READ VALUE USING GTS (HEADLIGHT DIMMER SWITCH)


    1. Using the GTS, read the Data List Click here.

      Main Body
      Tester Display Measurement Item/Range Normal Condition Diagnostic Note
      Dimmer SW Headlight dimmer switch high position signal / ON or OFF

      ON: Headlight dimmer switch in high or high flash position

      OFF: Headlight dimmer switch in low position

      		 -
      Passing Light SW Headlight dimmer switch high flash position (pass) signal / ON or OFF

      ON: Headlight dimmer switch in high flash position

      OFF: Headlight dimmer switch not in high flash position

      		 -
      Rear Fog Light SW* Rear fog light switch signal / ON or OFF

      ON: Rear fog light switch on

      OFF: Rear fog light switch off

      		 -
      Front Fog Light SW Front fog light switch signal / ON or OFF

      ON: Front fog light switch on

      OFF: Front fog light switch off

      		 -
      Auto Light SW Headlight dimmer switch AUTO position signal / ON or OFF

      ON: Headlight dimmer switch in AUTO position

      OFF: Headlight dimmer switch not in AUTO position

      		 -
      Head Light SW (Head) Headlight dimmer switch head position signal / ON or OFF

      ON: Headlight dimmer switch in head position

      OFF: Headlight dimmer switch not in head position

      		 -
      Head Light SW (Tail) Headlight dimmer switch tail position signal / ON or OFF

      ON: Headlight dimmer switch in tail or head position

      OFF: Headlight dimmer switch in neither tail nor head position

      		 -

      • *: w/ Rear Fog Light

      OK
      The display is as specified in the normal condition column.

    OK

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

    NG

  2. INSPECT HEADLIGHT DIMMER SWITCH ASSEMBLY (LIGHT CONTROL SWITCH, DIMMER SWITCH, FRONT FOG LIGHT SWITCH)


    1. Remove the headlight dimmer switch assembly Click here.

    2. Inspect the headlight dimmer switch assembly Click here.


    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] AND BODY GROUND)


    1. Disconnect the E14 headlight dimmer switch assembly connector.

    2. Disconnect the E118 main body ECU (multiplex network body ECU) connectors.

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

      Standard Resistance
      for LHD
      Tester Connection Condition Specified Condition
      E118-26 (FFOG) - E14-9 (BFG) Always Below 1 Ω
      E118-23 (RFOG) - E14-7 (B)
      E118-24 (HU) - E14-14 (HU)
      E118-10 (HF) - E14-17 (HF)
      E118-22 (TAIL) - E14-18 (T)
      E118-12 (HEAD) - E14-19 (H)
      E118-8 (A) - E14-20 (A)
      E14-8 (LFG) - Body ground)
      E14-15 (EL) - Body ground
      E118-26 (FFOG) - Body ground Always 10 kΩ or higher
      E118-23 (RFOG) - Body ground*
      E118-24 (HU) - Body ground
      E118-10 (HF) - Body ground
      E118-22 (TAIL) - Body ground
      E118-12 (HEAD) - Body ground
      E118-8 (A) - Body ground
      for RHD
      Tester Connection Condition Specified Condition
      E118-26 (FFOG) - E14-2 (BFG) Always Below 1 Ω
      E118-23 (RFOG) - E14-4 (B)
      E118-24 (HU) - E14-17 (HU)
      E118-10 (HF) - E14-14 (HF)
      E118-22 (TAIL) - E14-13 (T)
      E118-12 (HEAD) - E14-12 (H)
      E118-8 (A) - E14-11 (A)
      E14-3 (LFG) - Body ground)
      E14-16 (EL) - Body ground
      E118-26 (FFOG) - Body ground Always 10 kΩ or higher
      E118-23 (RFOG) - Body ground*
      E118-24 (HU) - Body ground
      E118-10 (HF) - Body ground
      E118-22 (TAIL) - Body ground
      E118-12 (HEAD) - Body ground
      E118-8 (A) - Body ground

      • *: w/ Rear Fog Light

      Result
      Result Proceed to
      OK A
      NG (for LHD) B
      NG (for RHD) C

    A

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    B

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

    C

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