METER / GAUGE SYSTEM Meter Illumination does not Dim at Night

DESCRIPTION

If the dimmer switch is turned to tail, head or AUTO, the main body ECU sends a TAIL relay signal, panel light illumination signal, panel relay signal, and TAIL cancel OFF signal to the combination meter. Then the meter and accessory meter become dim.

Tech Tips

TAIL cancel switch: When the headlights are illuminated and the TAIL cancel switch is turned off, the meter does not dim.

WIRING DIAGRAM

A01ES3QE05

INSPECTION PROCEDURE

PROCEDURE


  1. CHECK CAN COMMUNICATION SYSTEM


    1. Check for DTCs Click here.

      Result
      Result Proceed to
      CAN communication system DTC is not output A
      CAN communication system (for LHD) DTC is output B
      CAN communication system (for RHD) DTC is output C

    B
    C
    A
  2. 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
    OK
  3. 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 value(s) in 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
    OK
  4. CHECK HARNESS AND CONNECTOR (COMBINATION METER - LIGHT CONTROL RHEOSTAT AND BODY GROUND)


    1. A01ERLCE03

      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)
      E77-31 (TC) - E9-6 (TC)
      E77-32 (ILL+) or E9-5 (T) - Body ground Always 10 kΩ or higher
      E77-33 (TR) or E9-7 (TR) - Body ground
      E77-34 (E2) or E9-1 (E) - Body ground
      E77-31 (TC) or E9-6 (TC) - Body ground

    NG
    OK