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

DESCRIPTION

When the light control rheostat knob is turned to the left, the combination meter and vehicle interior illumination will dim. When the light control rheostat knob is turned to the right, the combination meter and vehicle illumination will become brighter.

WIRING DIAGRAM

A01ER0TE01

INSPECTION PROCEDURE

PROCEDURE


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


    1. Operate the intelligent tester according to the display and select the Data List Click here.

      Combination Meter
      Tester Display Measurement Item/Range Normal Condition Diagnostic Note
      Tail Cancel SW TAIL cancel switch condition/ON or OFF

      ON: TAIL cancel switch on

      OFF: TAIL cancel switch off

      		 -
      Rheostat value Light control rheostat switch input/Min.: 0, Max.: 100 Light control rheostat switch is fully turned left (0) → fully turned right (100) Unit: %
      OK
      Light brightness can be changed within specified range by manual operation.

    NG

    REPLACE COMBINATION METER ASSEMBLY Click here

    OK

  2. INSPECT LIGHT CONTROL RHEOSTAT


    1. Inspect the light control rheostat.

      A01ENOEE01

      1. Remove the light control rheostat Click here.

      2. Measure the resistance according to the table below.

        Standard Resistance
        Tester Connection Switch Condition Specified Condition
        6 (TC) - 5 (T) TAIL cancel switch off → on 10 kΩ or higher → Below 1 Ω
        5 (T) - 1 (E) Always 10 kΩ +/-20%
        7 (TR) - 1 (E) Light control rheostat fully turned right → fully turned left 10 kΩ +/-20% → Below 100 Ω

    NG

    REPLACE LIGHT CONTROL RHEOSTAT Click here

    OK

  3. CHECK HARNESS AND CONNECTOR (COMBINATION METER - LIGHT CONTROL RHEOSTAT)

    A01ERLCE02

    1. Disconnect the E77 meter connector.

    2. Disconnect the E9 rheostat connector.

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      E77-32 (ILL+) - E9-5 (T) Always Below 1 Ω
      E77-33 (TR) - E9-7 (TR)
      E77-34 (E2) - E9-1 (E)
      E7-31 (TC) - E9-6 (TC)

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    OK

  4. REPLACE COMBINATION METER ASSEMBLY


    1. Replace the combination meter assembly with a new or normally operating one Click here.

    2. Perform an operation inspection.

      OK
      Combination meter assembly operates normally.

    NG

    Go to LIGHTING SYSTEM Click here

    OK

    END (COMBINATION METER IS DEFECTIVE)