AUDIO AND VISUAL SYSTEM(for Radio Receiver Type) 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

A004Y1BE02
*a ACAN
*b ADIM
*c Radio Receiver Assembly
*d Main Body ECU (Multiplex Network Body ECU)

PROCEDURE


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


    1. Disconnect the radio receiver assembly connector.

    2. A004Y0IE02
      Text in Illustration
      *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
      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. A00500OE02
      Text in Illustration
      *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
      Tester Connection Condition Specified Condition
      H48-7 (GND) - Body ground Always Below 1 Ω

    OK

    REPLACE RADIO RECEIVER ASSEMBLY Click here

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

  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
      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

    OK

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

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR