AUDIO AND VISUAL SYSTEM (w/o Navigation System) Dimmer Signal Circuit

DESCRIPTION

The radio receiver assembly uses this circuit to communicate with the main body ECU (multiplex network body ECU) via a direct line. The main body ECU (multiplex network body ECU) uses this circuit to send an auto dimmer signal to the radio receiver assembly. The main body ECU (multiplex network body ECU) detects the position of the light control switch according to the resistance. When the light control switch is set to the head or tail position, the resistance between the head or tail terminal and body ground is below 1 Ω. When the light control switch is set to the head or tail position, the main body ECU (multiplex network body ECU) sends an auto dimmer signal to the radio receiver assembly. When the radio receiver assembly receives an auto dimmer signal from the main body ECU (multiplex network body ECU), the radio receiver assembly causes the instrument panel illumination to be dimmed.

WIRING DIAGRAM

A003X09E01

INSPECTION PROCEDURE

PROCEDURE


  1. INSPECT MAIN BODY ECU (MULTIPLEX NETWORK BODY ECU)


    1. Disconnect the radio receiver assembly connector.

    2. A003YPIE01
      Text in Illustration
      *A for 10 Speakers
      *B for 6 Speakers
      *a

      Front view of wire harness connector

      (to Radio Receiver Assembly)

      Measure the voltage according to the value(s) in the table below.

      Standard Voltage
      for 10 Speakers
      Tester Connection Condition Specified Condition
      H52-20 (ADIM) - Body ground Power switch on (IG), automatic light control sensor covered by hand, and light control switch in the tail or head position 11 to 14 V
      for 6 Speakers
      Tester Connection Condition Specified Condition
      H47-3 (ADIM) - Body ground Power switch on (IG), automatic light control sensor covered by hand, and light control switch in the tail or head position 11 to 14 V

    NG

    CHECK HARNESS AND CONNECTOR Click here

    OK

  2. INSPECT RADIO RECEIVER ASSEMBLY


    1. Disconnect the radio receiver assembly connector.

    2. A003YW1E01
      Text in Illustration
      *A for 10 Speakers
      *B for 6 Speakers
      *a

      Front view of wire harness connector

      (to Radio Receiver Assembly)

      Measure the resistance according to the value(s) in the table below

      Standard Resistance
      for 10 Speakers
      Tester Connection Condition Specified Condition
      H51-20 (GND) - Body ground Always Below 1 Ω
      for 6 Speakers
      Tester Connection Condition Specified Condition
      H48-7 (GND) - Body ground Always Below 1 Ω

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    OK

    REPLACE RADIO RECEIVER ASSEMBLY Click here

  3. CHECK HARNESS AND CONNECTOR


    1. Disconnect the radio receiver assembly and main body ECU (multiplex network body ECU) connectors.

    2. Measure the resistance according to the value(s) in the table below.

      Standard Resistance
      for 10 Speakers
      Tester Connection Condition Specified Condition
      H17-22 (ACAN) - H52-20 (ADIM) Always Below 1 Ω
      H52-20 (ADIM) - Body ground Always 10 kΩ or higher
      for 6 Speakers
      Tester Connection Condition Specified Condition
      H17-22 (ACAN) - H47-3 (ADIM) Always Below 1 Ω
      H47-3 (ADIM) - Body ground Always 10 kΩ or higher

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    OK

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