METER / GAUGE SYSTEM Operating Light Control Rheostat does not Change Light Brightness

DESCRIPTION

In this circuit, the meter CPU receives signals for adjusting illumination on the meter. The meter CPU detects the illumination level selected by pressing the light control up or light control down switch.

Tech Tips


  • This model is equipped with an optitron meter, therefore the meter illuminates even in the daytime.

  • The meter illumination level can be adjusted by pressing the light control up or light control down switch.

  • The meter illumination dims when the light control switch is turned to the TAIL or HEAD position at night.

  • The whole trip switch should be replaced if the light control up or down switch has a malfunction because this part is not independently supplied.

WIRING DIAGRAM

A01CE6BE04

INSPECTION PROCEDURE

PROCEDURE


  1. READ VALUE USING INTELLIGENT TESTER (LIGHT CONTROL UP SWITCH, LIGHT CONTROL DOWN SWITCH)


    1. Connect the intelligent tester to the DLC3.

    2. Turn the engine switch on (IG).

    3. Turn the tester on.

    4. Enter the following menus: Body / Combination Meter / Data List.

    5. Check the values by referring to the table below.

      Combination Meter
      Tester Display Measurement Item/Range Normal Condition Diagnostic Note
      Light Control Up Switch Light control up switch/OFF or ON OFF: Light control up switch released -
      ON: Light control up switch pressed -
      Light Control Down Switch Light control down switch/OFF or ON OFF: Light control down switch released -
      ON: Light control down switch pressed -
      OK
      Light control up or down switch condition displayed on the tester changes with the actual switch operation.

    NG

    CHECK HARNESS AND CONNECTOR (COMBINATION METER ASSEMBLY - TRIP SWITCH) Click here

    OK

    REPLACE COMBINATION METER ASSEMBLY Click here

  2. CHECK HARNESS AND CONNECTOR (COMBINATION METER ASSEMBLY - TRIP SWITCH)


    1. Disconnect the G19 and G32 connectors.

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      G19-8 (TR) - G32-2 (TR) Always Below 1 Ω
      G19-8 (TR) - Body ground Always 10 kΩ or higher
      G19-7 (TC) - G32-5 (T)*1 Always Below 1 Ω
      G19-7 (TC) - G32-5 (TC)*2 Always Below 1 Ω
      G19-7 (TC) - Body ground Always 10 kΩ or higher
      G32-4 (E) - Body ground Always Below 1 Ω

      • *1: for LHD

      • *2: for RHD


    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    OK

  3. INSPECT TRIP SWITCH (LIGHT CONTROL UP SWITCH, LIGHT CONTROL DOWN SWITCH)


    1. A01CDSSE06

      Remove the trip switch Click here.

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      4 (E) - 2 (TR) Light control up switch is pressed Below 1 Ω
      4 (E) - 2 (TR) Light control up switch is released 10 kΩ or higher
      4 (E) - 5 (T)*1 Light control down switch is pressed Below 1 Ω
      4 (E) - 5 (T)*1 Light control down switch is released 10 kΩ or higher
      4 (E) - 5 (TC)*2 Light control down switch is pressed Below 1 Ω
      4 (E) - 5 (TC)*2 Light control down switch is released 10 kΩ or higher

      • *1: for LHD

      • *2: for RHD

    3. Apply battery voltage from the wire harness back side between the terminals of the switch, and check the lighting condition of the trip switch.

      OK
      Tester Connection Condition Specified Condition

      Battery positive (+) → 8 (ILL+)

      Battery negative (-) → 4 (E)

      		 Always Trip switch illuminates

    NG

    REPLACE TRIP SWITCH Click here

    OK

    REPLACE COMBINATION METER ASSEMBLY Click here