METER / GAUGE SYSTEM Meter Illumination does not Dim at Night

DESCRIPTION

In this circuit, the combination meter assembly (meter circuit plate) receives auto dimmer signals from the main body ECU (multiplex network body ECU) via CAN communication. When the combination meter assembly (meter circuit plate) receives an auto dimmer signal, it dims the meter illumination (warning and indicator lights).

The main body ECU (multiplex network body ECU) determines whether it is daytime or nighttime based on the waveform transmitted from the automatic light control sensor. If the main body ECU (multiplex network body ECU) determines that it is nighttime and the headlight dimmer switch assembly is in the tail, head, or AUTO position, the ECU sends an auto dimmer signal to the combination meter assembly (meter circuit plate).

According to this signal, the combination meter assembly (meter circuit plate) dims the meter illumination.

Tech Tips

When the meter illumination does not dim at night, there may be a malfunction in the automatic light control sensor, main body ECU (multiplex network body ECU), CAN communication system, wire harness, connector, or combination meter assembly (meter circuit plate).

WIRING DIAGRAM

B004QD0E86
*1 Main Body ECU (Multiplex Network Body ECU)
*2 CAN Communication Line
*3 Combination Meter Assembly (Meter Circuit Plate)

CAUTION / NOTICE / HINT

Note

Before replacing the main body ECU (multiplex network body ECU), refer to Service Bulletin.

Tech Tips


  • The automatic light control sensor sensitivity can be customized.

    Click here

  • Setting the meter illumination level to maximum brightness prevents the meter illumination from dimming when the headlight dimmer switch assembly is changed to the tail, head, or AUTO position at night. Therefore, check the meter illumination setting before proceeding to the following steps.

PROCEDURE


  1. CHECK CAN COMMUNICATION SYSTEM


    1. Check if CAN communication DTCs are output.

      Click here

      Result
      Result Proceed to
      CAN communication DTCs are not output. A
      CAN communication DTCs are output. B

    B

    GO TO CAN COMMUNICATION SYSTEM Click here

    A

  2. CHECK FOR DTC


    1. Check if lighting system DTCs are output.

      Click here


      Body Electrical > Main Body > Trouble Codes
      Result
      Result Proceed to
      DTC B1244 is not output. A
      DTC B1244 is output. B

    B

    GO TO DTC B1244 Click here

    A

  3. REPLACE COMBINATION METER ASSEMBLY (METER CIRCUIT PLATE)


    1. Replace the combination meter assembly (meter circuit plate) with a new or known good one.

      Click here

      OK
      The operation of the combination meter assembly (meter circuit plate) returns to normal.
      Result
      Proceed to
      OK
      NG

    OK

    END

    NG

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