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/tail position, the resistance between the head/tail terminal and body ground is below 1Ω. When the light control switch is set to the head/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 instrument panel illumination.

WIRING DIAGRAM

A01NEUWE02

INSPECTION PROCEDURE

PROCEDURE


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


    1. A01NHEHE01
      Text in Illustration
      *1

      Front view of wire harness connector

      (to Radio Receiver Assembly)

      Disconnect the radio receiver assembly connector.

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

      Standard Voltage
      Tester Connection Condition Specified Condition
      G9-20 (ADIM) - Body ground Power switch on (IG), automatic light control sensor covered by hand, and light control switch 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. A01NDH5E24
      Text in Illustration
      *1

      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
      G7-20 (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. A01NEDFE01
      Text in Illustration
      *1

      Front view of wire harness connector

      (to Radio Receiver Assembly)
      *2

      Front view of wire harness connector

      (to Main Body ECU (Multiplex Network Body ECU))

      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
      F14-22 (ACAN) - G9-20 (ADIM) Always Below 1 Ω
      G9-20 (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