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

Toyota Tacoma 2015-2018 Service Manual / Audio / Video / Audio And Visual System / Microphone Circuit between Microphone and Radio Receiver

DESCRIPTION

The radio and display receiver assembly and telephone 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 telephone microphone assembly, and the telephone microphone assembly sends microphone signals to the radio and display receiver assembly.

WIRING DIAGRAM

PROCEDURE

1.	CHECK MICROPHONE

(a) Enter the "Microphone Check" screen.

Refer to Check Microphone in Operation Check.

Click here

(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 (RADIO AND DISPLAY RECEIVER ASSEMBLY - TELEPHONE MICROPHONE ASSEMBLY

(a) Disconnect the R31 radio and display receiver assembly connector.

(b) Disconnect the T26 telephone microphone assembly connector.

Standard Resistance:

Tester Connection	Condition	Specified Condition
R31-4 (MACC) - T26-1 (MACC)	Always	Below 1 Ω
R31-5 (MIN+) - T26-2 (MIC+)	Always	Below 1 Ω
R31-19 (MIN-) - T26-4 (MIC-)	Always	Below 1 Ω
R31-6 (SNS2) - T26-3 (SNS2)	Always	Below 1 Ω
R31-4 (MACC) - Body ground	Always	10 kΩ or higher
R31-5 (MIN+) - Body ground	Always	10 kΩ or higher
R31-19 (MIN-) - Body ground	Always	10 kΩ or higher
R31-18 (SGND) - Body ground	Always	10 kΩ or higher
R31-6 (SNS2) - Body ground	Always	10 kΩ or higher

(d) Reconnect the radio and display receiver assembly connector.

(e) Reconnect the telephone microphone assembly connector.

REPAIR OR REPLACE HARNESS OR CONNECTOR

3.	INSPECT RADIO AND DISPLAY RECEIVER ASSEMBLY

(a) Remove the radio and display receiver assembly with connectors still connected.

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

Standard Voltage:

Tester Connection	Switch Condition	Specified Condition
R31-4 (MACC) - Body ground	Ignition switch ACC	4 to 6 V

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

Standard Resistance:

Tester Connection	Condition	Specified Condition
R31-19 (MIN-) - Body ground	Always	Below 1 Ω
R31-18 (SGND) - Body ground	Always	Below 1 Ω

REPLACE RADIO AND DISPLAY RECEIVER ASSEMBLY

4.	INSPECT TELEPHONE MICROPHONE ASSEMBLY

(a) Remove the telephone microphone assembly.

Click here

*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

Click here

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 amplifier microphone assembly is output	A
A waveform synchronized with the voice input to the amplifier microphone assembly is not output	B

PROCEED TO NEXT SUSPECTED AREA SHOWN IN PROBLEM SYMPTOMS TABLE

REPLACE TELEPHONE MICROPHONE ASSEMBLY

Data Signal Circuit between Radio Receiver and Extension Module

DESCRIPTION The stereo component tuner assembly sends the image data signal to the radio and display receiver assembly via this circuit. WIRING DIAGRAM PROCEDURE 1. CHEC ...

Radio Receiver Power Source Circuit

DESCRIPTION This is the power source circuit to operate the radio and display receiver assembly. WIRING DIAGRAM CAUTION / NOTICE / HINT NOTICE: Inspect the fuses for circuits related to ...

Other materials:

Diagnostic Trouble Code Chart
DIAGNOSTIC TROUBLE CODE CHART Air Conditioning System DTC Code Detection Item Memory See page B1411/11 Room Temperature Sensor Circuit Memorized (4 seconds or more) B1412/12 ...

Customize Parameters
CUSTOMIZE PARAMETERS PROCEDURE 1. CUSTOMIZE THEFT DETERRENT SYSTEM (w/ Wireless Door Lock System) HINT: The following items can be customized. NOTICE: When the customer requests a change in a function, first make sure that the function can be customized. Be sure to make a note ...

Front Occupant Classification Sensor LH Circuit Malfunction (B1780)
DESCRIPTION The occupant classification sensor front LH circuit consists of the occupant detection ECU and the occupant classification sensor front LH. DTC B1780 is set when a malfunction is detected in the occupant classification sensor front LH circuit. DTC No. DTC Det ...