Dimmer Signal Circuit (to 12/2010)

AUDIO / VISUAL: AUDIO AND VISUAL SYSTEM: Dimmer Signal Circuit
- Dimmer Signal Circuit

DESCRIPTION

The radio receiver assembly uses this circuit to communicate with the body ECU via a direct line. The body ECU uses this circuit to send an auto dimmer signal to the radio receiver assembly. The 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 Ohms. When the light control switch is set to the head or tail position, the body ECU sends an auto dimmer signal to the radio receiver assembly. When the radio receiver assembly receives an auto dimmer signal from the body ECU, the radio receiver assembly causes the instrument panel illumination to be dimmed.

WIRING DIAGRAM





INSPECTION PROCEDURE

PROCEDURE

1. INSPECT BODY ECU

(a) Disconnect the radio receiver assembly connector.





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

Standard Voltage:





Text in Illustration





NG -- CHECK HARNESS AND CONNECTOR
OK -- Continue to next step.

2. INSPECT RADIO RECEIVER ASSEMBLY

(a) Disconnect the radio receiver assembly connector.

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





Standard Resistance:

for 12 Speakers





for 9 Speakers





Text in Illustration





NG -- REPAIR OR REPLACE HARNESS OR CONNECTOR

OK -- REPLACE RADIO RECEIVER ASSEMBLY Removal (to 12/2010)

3. CHECK HARNESS AND CONNECTOR

(a) Disconnect the radio receiver assembly and body ECU connectors.

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

Standard Resistance:





NG -- REPAIR OR REPLACE HARNESS OR CONNECTOR

OK -- REPLACE BODY ECU