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

DESCRIPTION

The No. 1 meter ECU receives signals for adjusting illumination on the meter of this circuit. The No. 1 meter ECU detects the illumination level selected by the user according to the switch operation.

Tech Tips

The meter illumination level can be adjusted by pushing the rheostat UP and DOWN switches.

WIRING DIAGRAM

A000TUCE01

PROCEDURE


  1. READ VALUE USING INTELLIGENT TESTER (LIGHT CONTROL RHEOSTAT)


    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 Electrical / Combination Meter / Data List.

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

      Combination meter
      Item Measurement Item / Range Normal Condition Diagnostic Note
      Light Control Up Switch Light control rheostat (UP) switch/ON or OFF

      ON: Light control rheostat (UP) switch pushed

      OFF: Light control rheostat (UP) switch not pushed

      		 -
      Light Control Down Switch Light control rheostat (DOWN) switch/ON or OFF

      ON: Light control rheostat (DOWN) switch pushed

      OFF: Light control rheostat (DOWN) switch not pushed

      		 -
      OK
      Switch condition (ON/OFF) can be switched by actual operation.

    OK

    REPLACE NO. 1 METER ECU Click here

    NG

  2. INSPECT LIGHT CONTROL RHEOSTAT

    A000Z2UE03
    *1 Component without harness connected: (Light Control Rheostat Switch)
    *2 UP
    *3 DOWN

    1. Remove the rheostat Click here.

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

      Standard resistance
      Tester Connection Switch Condition Specified Condition
      3 (UP) - 5 (E) UP switch is pushed Below 1 Ω
      UP switch is not pushed 10 kΩ or higher
      7 (DOWN) - 5 (E) DOWN switch pushed Below 1 Ω
      DOWN switch is not pushed 10 kΩ or higher

    NG

    REPLACE LIGHT CONTROL RHEOSTAT Click here

    OK

  3. CHECK HARNESS AND CONNECTOR (NO. 1 METER ECU - LIGHT CONTROL RHEOSTAT AND BODY GROUND)

    A000XESE03
    *1 Rear view of wire harness connector: (to No. 1 Meter ECU)
    *2 Rear view of wire harness connector: (to Light Control Rheostat)
    *3 UP
    *4 DOWN

    1. Disconnect the L124 meter connector.

    2. Disconnect the L8 rheostat connector.

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

      Standard resistance
      Tester Connection Condition Specified Condition
      L124-8 (RHUP) - L8-3 (UP) Always Below 1 Ω
      L124-7 (RHDW) - L8-7 (DOWN)
      L8-5 (E) - Body ground
      L124-8 (RHUP) or L8-3 (UP) - Body ground Always 10 kΩ or higher
      L124-7 (RHDW) or L8-7 (DOWN) - Body ground

    OK

    REPLACE NO. 1 METER ECU Click here

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR