LIGHTING SYSTEM Headlight Dimmer Switch Circuit

DESCRIPTION

The main body ECU receives the following signals:


WIRING DIAGRAM

A000T1BE13
A000T1BE14

CAUTION / NOTICE / HINT

Note


  • 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*1 Rear fog light switch signal / ON or OFF

      ON: Rear fog light switch on

      OFF: Rear fog light switch off

      		 -
      Front Fog Light SW*2 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

      		 -

      • *1: w/ Rear Fog Light

      • *2: w/ Front 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 Click here.

    2. Inspect the headlight dimmer switch Click here.


    NG

    REPLACE HEADLIGHT DIMMER SWITCH ASSEMBLY Click here

    OK

  3. CHECK HARNESS AND CONNECTOR (HEADLIGHT DIMMER SWITCH - MAIN BODY ECU AND BODY GROUND)


    1. Disconnect the N28 headlight dimmer switch connector.

    2. Disconnect the N12 and N13*1, *2 main body ECU connectors.


      • *1: w/ Front Fog Light

      • *2: w/ Rear Fog Light

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

      Standard Resistance
      for LHD
      Tester Connection Condition Specified Condition
      N12-27 (FFOG) - N28-11 (BFG)*1 Always Below 1 Ω
      N12-23 (RFOG) - N28-9 (B)*2 Always Below 1 Ω
      N12-5 (HU) - N28-18 (HU) Always Below 1 Ω
      N12-8 (HF) - N28-21 (HF) Always Below 1 Ω
      N12-30 (TAIL) - N28-22 (T) Always Below 1 Ω
      N12-29 (HEAD) - N28-23 (H) Always Below 1 Ω
      N12-28 (A) - N28-24 (A) Always Below 1 Ω
      N28-10 (LFG) - Body ground)*1, *2 Always Below 1 Ω
      N28-19 (EL) - Body ground Always Below 1 Ω
      N12-27 (FFOG) - Body ground*1 Always 10 kΩ or higher
      N13-23 (RFOG) - Body ground*2 Always 10 kΩ or higher
      N12-5 (HU) - Body ground Always 10 kΩ or higher
      N12-8 (HF) - Body ground Always 10 kΩ or higher
      N12-30 (TAIL) - Body ground Always 10 kΩ or higher
      N12-29 (HEAD) - Body ground Always 10 kΩ or higher
      N12-28 (A) - Body ground Always 10 kΩ or higher
      for RHD
      Tester Connection Condition Specified Condition
      N12-27 (FFOG) - N28-11 (BFG)*1, *3 Always Below 1 Ω
      N12-27 (FFOG) - N28-2 (BFG)*1, *4 Always Below 1 Ω
      N12-23 (RFOG) - N28-9 (B)*2, *3 Always Below 1 Ω
      N12-23 (RFOG) - N28-4 (B)*2, *4 Always Below 1 Ω
      N12-5 (HU) - N28-18 (HU)*3 Always Below 1 Ω
      N12-5 (HU) - N28-19 (HU)*4 Always Below 1 Ω
      N12-8 (HF) - N28-21 (HF)*3 Always Below 1 Ω
      N12-8 (HF) - N28-16 (HF)*4 Always Below 1 Ω
      N12-30 (TAIL) - N28-22 (T)*3 Always Below 1 Ω
      N12-30 (TAIL) - N28-15 (T)*4 Always Below 1 Ω
      N12-29 (HEAD) - N28-23 (H)*3 Always Below 1 Ω
      N12-29 (HEAD) - N28-14 (H)*4 Always Below 1 Ω
      N12-28 (A) - N28-24 (A)*3 Always Below 1 Ω
      N12-28 (A) - N28-13 (A)*4 Always Below 1 Ω
      N28-10 (LFG) - Body ground)*1, *2, *3 Always Below 1 Ω
      N28-3 (LFG) - Body ground)*1, *2, *4 Always Below 1 Ω
      N28-19 (EL) - Body ground*3 Always Below 1 Ω
      N28-18 (EL) - Body ground*4 Always Below 1 Ω
      N12-27 (FFOG) - Body ground*1 Always 10 kΩ or higher
      N13-23 (RFOG) - Body ground*2 Always 10 kΩ or higher
      N12-5 (HU) - Body ground Always 10 kΩ or higher
      N12-8 (HF) - Body ground Always 10 kΩ or higher
      N12-30 (TAIL) - Body ground Always 10 kΩ or higher
      N12-29 (HEAD) - Body ground Always 10 kΩ or higher
      N12-28 (A) - Body ground Always 10 kΩ or higher

      • *1: w/ Front Fog Light

      • *2: w/ Rear Fog Light

      • *3: for LH Side

      • *4: for RH Side


    OK

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

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR