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

for Preparation Click here


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


E222804E01


INSPECTION PROCEDURE

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

  1. Disconnect the radio receiver assembly connector.



    E222805E01

  1. 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

    Text in Illustration 
    *A
    		for 10 Speakers
    *B
    		for 6 Speakers
    *a
    		Front view of wire harness connector
    (to Radio Receiver Assembly)



NG
Go to step 3
OK


2.INSPECT RADIO RECEIVER ASSEMBLY

  1. Disconnect the radio receiver assembly connector.



    E222806E01

  1. 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

    Text in Illustration 
    *A
    		for 10 Speakers
    *B
    		for 6 Speakers
    *a
    		Front view of wire harness connector
    (to Radio Receiver Assembly)



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.

  1. 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)