METER / GAUGE SYSTEM Meter Illumination is Always Dark

DESCRIPTION

The meter ECU receives signals from this circuit to adjust the illumination of the meter. The meter ECU sets the illumination level based on the user operation of the light control rheostat switch.

Tech Tips


  • The meter illumination level can be adjusted by operating the light control rheostat switch.

  • The meter illumination dims when the light control switch is turned to the tail, head, or AUTO position.

  • Setting the meter illumination to maximum brightness cancels the above dimming of the meter illumination.

WIRING DIAGRAM

A01HPUOE73

INSPECTION PROCEDURE

Tech Tips


  • The meter illumination can be customized by turning the light control rheostat switch.

  • Setting the meter illumination to minimum brightness turns off (very dim) the meter illumination when the light control switch is changed to the tail, head, or AUTO position.

  • Before starting the following inspection, check if the lighting system outputs the DTCs Click here.

PROCEDURE


  1. CHECK CAN COMMUNICATION SYSTEM


    1. Check if a CAN communication DTC is output Click here.

      Result
      Result Proceed to
      CAN communication DTC is not output. A
      CAN communication DTC is output. B

    B

    GO TO CAN COMMUNICATION SYSTEM Click here

    A

  2. READ VALUE USING TECHSTREAM (ILLUMINATION RATE INFO)


    1. Connect the Techstream to the DLC3.

    2. Turn the ignition switch to ON.

    3. Turn the Techstream on.

    4. Enter the following menus: Body Electrical / Main Body / Data List.

    5. Check the values by referring to the table below.

      Main Body
      Tester Display Measurement Item/Range Normal Condition Diagnostic Note
      Illumination Rate Info Illumination rate information/0 ms. to 2162.65 ms. Value output according to ambient light level -
      Result
      Result Proceed to
      The output value changes according to the ambient light level. A
      The output value does not change according to the ambient light level. B

    B

    CHECK LIGHTING SETTING Click here

    A

  3. REPLACE MAIN BODY ECU (MULTIPLEX NETWORK BODY ECU)


    1. Replace the main body ECU (multiplex network body ECU) with a new or a known good one Click here.

      OK
      The operation of the combination meter assembly returns to normal.

      Tech Tips

      The meter ECU controls the meter illumination based on an auto dimmer signal from the main body ECU (multiplex network body ECU). When the meter illumination is always dark (very dim), it may be due to the main body ECU (multiplex network body ECU) sending an auto dimmer signal to the meter ECU because of a malfunction in the main body ECU (multiplex network body ECU).


    NG

    REPLACE COMBINATION METER ASSEMBLY Click here

    OK

    END