METER / GAUGE SYSTEM Meter Illumination is Always Dark

DESCRIPTION

In this circuit, the No. 1 meter ECU receives auto dimmer signals from the main body ECU using the CAN communication lines. When the meter CPU 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 daytime.

Tech Tips

When the meter illumination does not dim at night, the light control rheostat position is at 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 No. 1 meter ECU.

WIRING DIAGRAM

A01GW5KE07

INSPECTION PROCEDURE

PROCEDURE


  1. CHECK CAN COMMUNICATION SYSTEM


    1. Check for DTC Click here [for LHD], Click here [for RHD]).

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

    B

    Go to CAN COMMUNICATION SYSTEM Click here

    C

    Go to CAN COMMUNICATION SYSTEM Click here

    D

    Go to LIGHTING SYSTEM Click here

    A

  2. PERFORM ACTIVE TEST USING INTELLIGENT TESTER (DIMMER SIGNAL)


    1. Operate the intelligent tester according to the display and select "Active Test".

      Main Body
      Tester Display Test Part Control Range
      Dimmer signal Dimmer switch 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.


    NG

    REPLACE NO. 1 METER ECU Click here

    OK

    CHECK LIGHTING SETTING Click here

  3. REPLACE NO. 1 METER ECU


    1. Temporarily replace the No. 1 meter ECU with a new one Click here.


    NEXT

  4. CHECK NO. 1 METER ECU


    1. Check that the operation of the No. 1 meter ECU returns to normal Click here.

      OK
      Operation of No. 1 meter ECU returns to normal.

    NG

    REPLACE MAIN BODY ECU (DRIVER SIDE JUNCTION BLOCK)

    OK

    END (NO. 1 METER ECU IS DEFECTIVE)