METER / GAUGE SYSTEM Meter Illumination is Always Dark

DESCRIPTION

w/ Multi-information Display:

In this circuit, the combination meter assembly receives auto dimmer signals from the main body ECU using the CAN communication lines. When the combination meter assembly receives an auto dimmer signal, it dims the meter illumination. The main body ECU determines whether it is daytime, twilight or nighttime based on the waveform transmitted from the automatic light control sensor. If the main body ECU determines that it is daytime, the ECU does not send auto dimmer signals. Therefore, the meter illumination (warning and indicator lights) will not dim even if the driver accidentally turns the light control switch to the TAIL or HEAD position in the daytime.

Tech Tips

When the meter illumination does not dim at night, the light control rheostat position is in the TAIL cancel position, or there may be a malfunction in the automatic light control sensor, main body ECU, CAN communication system, wire harness or connector, or combination meter.

WIRING DIAGRAM

A01X2E0E04
*a CAN Line
*b Automatic Light Control Sensor
*c Main Body ECU (Multiplex Network Body ECU)
*d Combination Meter Assembly

PROCEDURE


  1. CHECK CAN COMMUNICATION SYSTEM


    1. Check for DTCs Click here.

      Result
      Result Proceed to
      DTC is not output A
      CAN communication system DTC is output B
      Lighting system DTC (B1244) is output C

      Tech Tips

      *: Refer to CAN communication system:



    B

    GO TO CAN COMMUNICATION SYSTEM*

    C

    GO TO LIGHTING SYSTEM Click here

    A

  2. PERFORM ACTIVE TEST USING GTS (DIMMER SWITCH)


    1. Operate the GTS according to the display and select Active Test.

      Main Body
      Tester Display Test Part Control Range Diagnostic Note
      Dimmer Signal Illumination dimming operation ON or OFF -
      OK
      Meter illumination is dimmed when the dimmer switch is ON.

      Tech Tips

      Refer to the sensitivity setting in the customization table of the automatic light control system Click here.

      Result
      Result Proceed to
      NG A
      OK B

    NG

    CHECK LIGHTING SETTING Click here

    OK

  3. CHECK COMBINATION METER ASSEMBLY


    1. Replace the combination meter with a new one Click here.

    2. Check that the operation of the combination meter returns to normal Click here.

      OK
      Operation of combination meter returns to normal.
      Result
      Result Proceed to
      OK A
      NG (for LHD) B
      NG (for RHD) C

    A

    END (COMBINATION METER IS DEFECTIVE)

    B

    REPLACE MAIN BODY ECU (MULTIPLEX NETWORK BODY ECU) Click here

    C

    REPLACE MAIN BODY ECU (MULTIPLEX NETWORK BODY ECU) Click here