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

DESCRIPTION

The meter ECU (No. 3 meter circuit plate) receives signals from this circuit to adjust the illumination of the meter, instrument panel, and headup display (combination meter mirror ECU). The meter ECU (No. 3 meter circuit plate) sets the illumination level based on the user operation of the light control rheostat.

Tech Tips

The meter illumination level can be adjusted by operating the trip switch.

WIRING DIAGRAM

A01J9SGE06

INSPECTION PROCEDURE

PROCEDURE


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


    1. Connect the intelligent tester to the DLC3.

    2. Turn the power switch on (IG).

    3. Turn the intelligent 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 Down SW Light control rheostat down switch/OFF or ON OFF: Light control rheostat down switch not pressed -
      ON: Light control rheostat down switch pressed
      Light Control Switch Display contrast adjust switch/OFF or ON OFF: Display contrast adjust switch not pressed -
      ON: Display contrast adjust switch pressed
      OK
      The value displayed on the intelligent tester gradually changes as the actual trip switch operation.

    NG

    INSPECT TRIP SWITCH Click here

    OK

    REPLACE COMBINATION METER ASSEMBLY (NO. 3 METER CIRCUIT PLATE) Click here

  2. INSPECT TRIP SWITCH


    1. Remove the trip switch.

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

      Standard Resistance
      Tester Connection Switch Condition Specified Condition
      8 (E) - 3 (TR) Trip switch not pressed 10 kΩ or higher
      Trip switch not pressed Below 1 Ω
      Text in Illustration
      *1

      Component without harness connected

      (Trip Switch)

    NG

    REPLACE TRIP SWITCH Click here

    OK

  3. CHECK HARNESS AND CONNECTOR (NO. 3 METER CIRCUIT PLATE - TRIP SWITCH)


    1. Disconnect the L27 and L57 connectors.

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      L27-37 (SW2) - L59-3 (TR) Always Below 1 Ω
      L27-37 (SW2) - Body ground Always 10 kΩ or higher
      L27-38 (SW3) - L59-8 (E) Always Below 1 Ω
      L27-38 (SW3) - Body ground Always 10 kΩ or higher

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    OK

    REPLACE COMBINATION METER ASSEMBLY (NO. 3 METER CIRCUIT PLATE) Click here