Toyota Venza: Microphone Circuit between Microphone and Radio Receiver

Toyota Venza Service Manual / Audio / Video / Audio And Visual System / Microphone Circuit between Microphone and Radio Receiver

DESCRIPTION

The radio and display receiver assembly and inner rear view mirror assembly (amplifier microphone assembly) are connected to each other using the microphone connection detection signal lines.

Using this circuit, the radio and display receiver assembly sends power to the inner rear view mirror assembly (amplifier microphone assembly), and the inner rear view mirror assembly (amplifier microphone assembly) sends microphone signals to the radio and display receiver assembly.

WIRING DIAGRAM

PROCEDURE

1.	CHECK MICROPHONE (OPERATION CHECK)

(a) Enter the "Microphone Check" screen. Refer to Check Microphone in Operation Check (See page ).

(b) When a voice is input into the microphone, check that the microphone input level meter changes according to the input voice.

OK:

Check result is normal.

REPLACE RADIO AND DISPLAY RECEIVER ASSEMBLY

2.	CHECK HARNESS AND CONNECTOR (RADIO AND DISPLAY RECEIVER ASSEMBLY - INNER REAR VIEW MIRROR ASSEMBLY (AMPLIFIER MICROPHONE ASSEMBLY)

(a) Disconnect the E42 radio and display receiver assembly connector.

(b) Disconnect the P12 inner rear view mirror assembly (amplifier microphone assembly) connector.

Standard Resistance:

Tester Connection	Condition	Specified Condition
E42-4 (MACC) - P12-9 (ACC)	Always	Below 1 Ω
E42-5 (MIN+) - P12-11 (MIC+)	Always	Below 1 Ω
E42-19 (MIN-) - P12-12 (MIC-)	Always	Below 1 Ω
E42-6 (SNS2) - P12-10 (SGND)	Always	Below 1 Ω
E42-4 (MACC) - Body ground	Always	10 kΩ or higher
E42-5 (MIN+) - Body ground	Always	10 kΩ or higher
E42-19 (MIN-) - Body ground	Always	10 kΩ or higher
E42-18 (SGND) - Body ground	Always	10 kΩ or higher
E42-6 (SNS2) - Body ground	Always	10 kΩ or higher

REPAIR OR REPLACE HARNESS OR CONNECTOR

3.	INSPECT RADIO AND DISPLAY RECEIVER ASSEMBLY

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

Standard Voltage:

Tester Connection	Condition	Specified Condition
E42-4 (MACC) - Body ground	Ignition switch ACC	4 to 6 V

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

Standard Resistance:

Tester Connection	Condition	Specified Condition
E42-18 (SGND) - Body ground	Always	Below 1 Ω
E42-19 (MIN-) - Body ground	Always	Below 1 Ω

Text in Illustration

*a	Component with harness connected (Radio and Display Receiver Assembly)

REPLACE RADIO AND DISPLAY RECEIVER ASSEMBLY

4.	INSPECT INNER REAR VIEW MIRROR ASSEMBLY (AMPLIFIER MICROPHONE ASSEMBLY)

(a) Remove the inner rear view mirror assembly (amplifier microphone assembly) (See page ).

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

Standard Resistance:

Tester Connection	Condition	Specified Condition
10 (SGND) - 12 (MIC-)	Always	Below 1 Ω

Text in Illustration

*a	Component without harness connected (Inner Rear View Mirror Assembly (Amplifier Microphone Assembly))

REPLACE INNER REAR VIEW MIRROR ASSEMBLY (AMPLIFIER MICROPHONE ASSEMBLY)

5.	INSPECT INNER REAR VIEW MIRROR ASSEMBLY (AMPLIFIER MICROPHONE ASSEMBLY)

(a) Turn the ignition switch to ACC.

(b) Connect an oscilloscope to terminals 11 (MIC+) and 12 (MIC-) of the P12 inner rear view mirror assembly (amplifier microphone assembly) connector.

Result	Proceed to
A waveform synchronized with the voice input to the inner rear view mirror assembly (amplifier microphone assembly) is output.	A
A waveform synchronized with the voice input to the inner rear view mirror assembly (amplifier microphone assembly) is not output.	B

Text in Illustration

*a	Component with harness connected (Inner Rear View Mirror Assembly (Amplifier Microphone Assembly))

PROCEED TO NEXT SUSPECTED AREA SHOWN IN PROBLEM SYMPTOMS TABLE

REPLACE INNER REAR VIEW MIRROR ASSEMBLY (AMPLIFIER MICROPHONE ASSEMBLY)

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