Toyota Tacoma 2015-2018 Service Manual: Microphone Circuit between Microphone and Radio Receiver

Toyota Tacoma 2015-2018 Service Manual / Navigation / Multi Info Display / Navigation System / Microphone Circuit between Microphone and Radio Receiver

DESCRIPTION

The navigation receiver assembly and telephone microphone assembly are connected to each other using the microphone connection detection signal lines.

Using this circuit, the navigation receiver assembly sends power to the telephone microphone assembly and the telephone microphone assembly sends microphone signals to the navigation receiver assembly.

WIRING DIAGRAM

PROCEDURE

1.	CHECK MICROPHONE

(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.

PROCEED TO NEXT SUSPECTED AREA SHOWN IN PROBLEM SYMPTOMS TABLE

2.	CHECK HARNESS AND CONNECTOR (NAVIGATION RECEIVER ASSEMBLY - TELEPHONE MICROPHONE ASSEMBLY)

(a) Disconnect the N25 navigation receiver assembly connector.

(b) Disconnect the T26 telephone microphone assembly connector.

Standard Resistance:

Tester Connection	Condition	Specified Condition
N25-4 (MACC) - T26-1 (MACC)	Always	Below 1 Ω
N25-5 (MIN+) - T26-2 (MIC+)	Always	Below 1 Ω
N25-19 (MIN-) - T26-4 (MIC-)	Always	Below 1 Ω
N25-6 (SNS2) - T26-3 (SNS2)	Always	Below 1 Ω
N25-4 (MACC) - Body ground	Always	10 kΩ or higher
N25-5 (MIN+) - Body ground	Always	10 kΩ or higher
N25-19 (MIN-) - Body ground	Always	10 kΩ or higher
N25-18 (SGND) - Body ground	Always	10 kΩ or higher
N25-6 (SNS2) - Body ground	Always	10 kΩ or higher

(d) Reconnect the navigation receiver assembly connector.

(e) Reconnect the telephone microphone assembly connector.

REPAIR OR REPLACE HARNESS OR CONNECTOR

3.	INSPECT NAVIGATION RECEIVER ASSEMBLY

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

Standard Voltage:

Tester Connection	Switch Condition	Specified Condition
N25-4 (MACC) - Body ground	Ignition switch ACC	4 to 6 V

*a	Component with harness connected (Navigation Receiver Assembly)

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

Standard Resistance:

Tester Connection	Condition	Specified Condition
N25-19 (MIN-) - Body ground	Always	Below 1 Ω
N25-18 (SGND) - Body ground	Always	Below 1 Ω

REPLACE NAVIGATION RECEIVER ASSEMBLY

4.	INSPECT TELEPHONE MICROPHONE ASSEMBLY

(a) Remove the telephone microphone assembly (See page ).

*a	Component without harness connected (Telephone Microphone Assembly)

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

Standard Resistance:

Tester Connection	Condition	Specified Condition
3 (SNS2) - 4 (MIC-)	Always	Below 1 Ω

REPLACE TELEPHONE MICROPHONE ASSEMBLY

5.	INSPECT TELEPHONE MICROPHONE ASSEMBLY

(a) Turn the ignition switch to ACC.

*a	Component with harness connected (Telephone Microphone Assembly)

(b) Connect an oscilloscope to terminals 2 (MIC+) and 4 (MIC-) of the telephone microphone assembly connector.

Result

Result	Proceed to
A waveform synchronized with the voice input to the telephone microphone assembly is output	A
A waveform synchronized with the voice input to the telephone microphone assembly is not output	B

PROCEED TO NEXT SUSPECTED AREA SHOWN IN PROBLEM SYMPTOMS TABLE

REPLACE TELEPHONE MICROPHONE ASSEMBLY

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