METER / GAUGE SYSTEM Meter Illumination is Always Dark

DESCRIPTION

In this circuit, the combination meter assembly receives auto dimmer signals from the main body ECU through the CAN communication line when the headlight dimmer switch is set to AUTO. When the combination meter 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 that is built into the rain sensor. If the main body ECU determines that it is daytime, the ECU does not send auto dimmer signals.

Tech Tips

When the meter illumination does not dim at night even if the headlight dimmer switch is set to AUTO, there may be a malfunction in the rain sensor, main body ECU, CAN communication system, wire harnesses, connectors or combination meter assembly.

WIRING DIAGRAM

A0053R5E03
*1 Main Body ECU (Instrument Panel Junction Block Assembly)
*2 Combination Meter Assembly
*3 CAN Communication Line

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

    B

    Go to CAN COMMUNICATION SYSTEM Click here

    C

    Go to LIGHTING SYSTEM Click here

    A

  2. READ VALUE USING INTELLIGENT TESTER (DIMMER SWITCH)


    1. Use the Data List to check if the headlight dimmer switch is operating properly Click here.

      Main Body
      Tester Display Measurement Item/Range Normal Condition Diagnostic Note
      Dimmer SW Dimmer switch signal / ON or OFF

      ON: Dimmer switch on

      OFF: Dimmer switch off

      		 -
      OK
      Tester display changes according to operation of headlight dimmer switch.

      Tech Tips

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


    OK

    CHECK LIGHTING SETTING

    NG

  3. REPLACE COMBINATION METER ASSEMBLY


    1. Temporarily replace the combination meter with a new or normally functioning one Click here.


    NEXT

  4. CHECK COMBINATION METER ASSEMBLY


    1. Perform an operation check and check that the operation of the combination meter returns to normal Click here.

      OK
      Operation of combination meter returns to normal.

    OK

    END (COMBINATION METER IS DEFECTIVE)

    NG

    REPLACE MAIN BODY ECU (INSTRUMENT PANEL JUNCTION BLOCK ASSEMBLY)