AUDIO / VIDEO: AUDIO AND VISUAL SYSTEM (for Gasoline Model with Dual Knob Type): Microphone Circuit; 2021 - 2023 MY Corolla Corolla Hatchback GR Corolla [04/2020

Last Modified: 07-31-2024	6.11:8.1.0	Doc ID: RM100000001N26H
Model Year Start: 2021	Model: GR Corolla	Prod Date Range: [04/2020 - 11/2022]
Title: AUDIO / VIDEO: AUDIO AND VISUAL SYSTEM (for Gasoline Model with Dual Knob Type): Microphone Circuit; 2021 - 2023 MY Corolla Corolla Hatchback GR Corolla [04/2020 - 11/2022]

Microphone Circuit

DESCRIPTION

w/o Manual (SOS) Switch:
The radio and display receiver sub-assembly, map light 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 map light assembly and telephone microphone assembly, and the map light assembly and telephone microphone assembly sends microphone signals to the radio and display receiver assembly.
w/ Manual (SOS) Switch:
The radio and display receiver assembly, map light assembly and telephone microphone assembly are connected to each other using the microphone connection detection signal lines.

Using this circuit, the DCM (telematics transceiver) sends power to the map light assembly and telephone microphone assembly, and the map light assembly and telephone microphone assembly sends microphone signals to the radio and display receiver assembly via the DCM (telematics transceiver).

WIRING DIAGRAM

CAUTION / NOTICE / HINT

NOTICE:

Depending on the parts that are replaced during vehicle inspection or maintenance, performing initialization, registration or calibration may be needed. Refer to Precaution for Audio and Visual System.
Click here
When replacing the radio and display receiver assembly, always replace it with a new one. If a radio and display receiver assembly which was installed to another vehicle is used, the following may occur:
- A communication malfunction DTC may be stored.
- The radio and display receiver assembly may not operate normally.
Before replacing the DCM (telematics transceiver), refer to Registration.
Click here

PROCEDURE

1.	CHECK MICROPHONE (OPERATION CHECK)

(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.

Result	Proceed to
NG (w/o Manual (SOS) Switch)	A
NG (w/ Manual (SOS) Switch)	B
OK	C

GO TO STEP 8

REPLACE RADIO AND DISPLAY RECEIVER ASSEMBLY

2.	CHECK HARNESS AND CONNECTOR (RADIO AND DISPLAY RECEIVER ASSEMBLY - MAP LIGHT ASSEMBLY)

(a) Disconnect the I56 radio and display receiver assembly connector.

(b) Disconnect the T6 map light assembly connector.

Standard Resistance:

Tester Connection	Condition	Specified Condition
I56-25 (SNS2) - T6-4 (SNS2)	Always	Below 1 Ω
I56-23 (MACC) - T6-7 (MACC)	Always	Below 1 Ω
I56-21 (MIN+) - T6-6 (MCO+)	Always	Below 1 Ω
I56-22 (MIN-) - T6-5 (MCO-)	Always	Below 1 Ω
I56-25 (SNS2) or T6-4 (SNS2) - Body ground	Always	10 kΩ or higher
I56-23 (MACC) or T6-7 (MACC) - Body ground	Always	10 kΩ or higher
I56-21 (MIN+) or T6-6 (MCO+) - Body ground	Always	10 kΩ or higher
I56-22 (MIN-) or T6-5 (MCO-) - Body ground	Always	10 kΩ or higher
I56-24 (SGND) - Body ground	Always	10 kΩ or higher

REPAIR OR REPLACE HARNESS OR CONNECTOR

3.	INSPECT RADIO AND DISPLAY RECEIVER ASSEMBLY

(a) Connect the I56 radio and display receiver assembly connector.

(b) Connect the T6 map light assembly connector.

Standard Voltage:

Tester Connection	Condition	Specified Condition
I56-23 (MACC) - Body ground	Ignition switch ACC	4 to 6 V

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

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

Standard Resistance:

Tester Connection	Condition	Specified Condition
I56-24 (SGND) - Body ground	Always	Below 1 Ω
I56-22 (MIN-) - Body ground	Always	Below 1 Ω

REPLACE RADIO AND DISPLAY RECEIVER ASSEMBLY

4.	INSPECT MAP LIGHT ASSEMBLY

(a) Remove the map light assembly.

Click here

(b) Connect the B telephone microphone assembly connector.

Standard Resistance:

Tester Connection	Condition	Specified Condition
4 (SNS2) - 5 (MCO-)	Always	Below 1 Ω

*a	Component without harness connected (Map Light Assembly)

GO TO STEP 7

5.	INSPECT MAP LIGHT ASSEMBLY (OUTPUT TO RADIO AND DISPLAY RECEIVER ASSEMBLY)

(a) Connect the I56 radio and display receiver assembly connector.

(b) Connect the T6 map light assembly connector.

(d) Connect an oscilloscope to terminals 6 (MCO+) and 5 (MCO-) of the T6 map light assembly connector.

*a	Component with harness connected (Map Light Assembly)

(e) Check the signal waveform according to the condition(s) in the table below.

Item	Condition
Measurement terminal	T6-6 (MCO+) - T6-5 (MCO-)
Tool setting	50 mV/DIV., 500 ms/DIV.
Vehicle condition	Turn the ignition switch to ACC. Sound is input to the map light assembly when the user is closer than 125 mm from the map light assembly sound holes.

OK:

The waveform is similar to that shown in the illustration.

HINT:

The oscilloscope waveform shown in the illustration is an example for reference only.

PROCEED TO NEXT SUSPECTED AREA SHOWN IN PROBLEM SYMPTOMS TABLE

6.	INSPECT MAP LIGHT ASSEMBLY

(a) Remove the map light assembly.

Click here

(b) Disconnect the B telephone microphone assembly connector.

Standard Resistance:

Tester Connection	Condition	Specified Condition
T6-6 (MCO+) - B-3	Always	Below 1 Ω
T6-5 (MCO-) - B-2	Always	Below 1 Ω
T6-6 (MCO+) or B-3 - T6-11 (GND)	Always	10 kΩ or higher
T6-5 (MCO-) or B-2 - T6-11 (GND)	Always	10 kΩ or higher

Component without harness connected

(Map Light Assembly (No. 1 Roof Wire Side))

Component without harness connected

(Map Light Assembly (Telephone Microphone Assembly Side))

REPLACE TELEPHONE MICROPHONE ASSEMBLY

REPLACE MAP LIGHT ASSEMBLY

7.	INSPECT MAP LIGHT ASSEMBLY

(a) Remove the map light assembly.

Click here

(b) Disconnect the B telephone microphone assembly connector.

Standard Resistance:

Tester Connection	Condition	Specified Condition
T6-4 (SNS2) - B-1	Always	Below 1 Ω
T6-5 (MCO-) - B-2	Always	Below 1 Ω
T6-4 (SNS2) or B-1 - T6-11 (GND)	Always	10 kΩ or higher
T6-5 (MCO-) or B-2 - T6-11 (GND)	Always	10 kΩ or higher

Component without harness connected

(Map Light Assembly (No. 1 Roof Wire Side))

Component without harness connected

(Map Light Assembly (Telephone Microphone Assembly Side))

REPLACE TELEPHONE MICROPHONE ASSEMBLY

REPLACE MAP LIGHT ASSEMBLY

8.	CHECK HARNESS AND CONNECTOR (RADIO AND DISPLAY RECEIVER ASSEMBLY - MAP LIGHT ASSEMBLY)

(a) Disconnect the I56 radio and display receiver assembly connector.

(b) Disconnect the T6 map light assembly connector.

Standard Resistance:

Tester Connection	Condition	Specified Condition
I56-25 (SNS2) - T6-4 (SNS2)	Always	Below 1 Ω
I56-25 (SNS2) or T6-4 (SNS2) - Body ground	Always	10 kΩ or higher

REPAIR OR REPLACE HARNESS OR CONNECTOR

9.	CHECK HARNESS AND CONNECTOR (RADIO AND DISPLAY RECEIVER ASSEMBLY - DCM (TELEMATICS TRANSCEIVER))

(a) Disconnect the I56 radio and display receiver assembly connector.

(b) Disconnect the I143 DCM (telematics transceiver) connector.

Standard Resistance:

Tester Connection	Condition	Specified Condition
I56-21 (MIN+) - I143-16 (MCO+)	Always	Below 1 Ω
I56-22 (MIN-) - I143-32 (MCO-)	Always	Below 1 Ω
I56-21 (MIN+) or I143-16 (MCO+) - Body ground	Always	10 kΩ or higher
I56-22 (MIN-) or I143-32 (MCO-) - Body ground	Always	10 kΩ or higher
I56-24 (SGND) - Body ground	Always	10 kΩ or higher

REPAIR OR REPLACE HARNESS OR CONNECTOR

10.	CHECK HARNESS AND CONNECTOR (DCM (TELEMATICS TRANSCEIVER) - MAP LIGHT ASSEMBLY)

(a) Disconnect the I143 DCM (telematics transceiver) connector.

(b) Disconnect the T6 map light assembly connector.

Standard Resistance:

Tester Connection	Condition	Specified Condition
I143-5 (MCVD) - T6-7 (MACC)	Always	Below 1 Ω
I143-6 (MCI+) - T6-6 (MCO+)	Always	Below 1 Ω
I143-7 (MCI-) - T6-5 (MCO-)	Always	Below 1 Ω
I143-5 (MCVD) or T6-7 (MACC) - Body ground	Always	10 kΩ or higher
I143-6 (MCI+) or T6-6 (MCO+) - Body ground	Always	10 kΩ or higher
I143-7 (MCI-) or T6-5 (MCO-) - Body ground	Always	10 kΩ or higher
I143-23 (SGND) - Body ground	Always	10 kΩ or higher

REPAIR OR REPLACE HARNESS OR CONNECTOR

11.	INSPECT RADIO AND DISPLAY RECEIVER ASSEMBLY

(a) Disconnect the I143 DCM (telematics transceiver) connector.

(b) Connect the I56 radio and display receiver assembly connector.

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

Standard Resistance:

Tester Connection	Condition	Specified Condition
I56-24 (SGND) - Body ground	Always	Below 1 Ω
I56-22 (MIN-) - Body ground	Always	Below 1 Ω

REPLACE RADIO AND DISPLAY RECEIVER ASSEMBLY

12.	INSPECT DCM (TELEMATICS TRANSCEIVER)

(a) Connect the I143 DCM (telematics transceiver) connector.

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

Standard Voltage:

Tester Connection	Condition	Specified Condition
I143-5 (MCVD) - Body ground	Ignition switch ACC	4 to 6 V

*a	Component with harness connected (DCM (Telematics Transceiver))

Standard Resistance:

Tester Connection	Condition	Specified Condition
I143-7 (MCI-) - Body ground	Always	Below 1 Ω
I143-23 (SGND) - Body ground	Always	Below 1 Ω

REPLACE DCM (TELEMATICS TRANSCEIVER)

13.	INSPECT MAP LIGHT ASSEMBLY

(a) Remove the map light assembly.

Click here

(b) Connect the B telephone microphone assembly connector.

Standard Resistance:

Tester Connection	Condition	Specified Condition
4 (SNS2) - 5 (MCO-)	Always	Below 1 Ω

*a	Component without harness connected (Map Light Assembly)

GO TO STEP 17

14.	INSPECT MAP LIGHT ASSEMBLY (OUTPUT TO DCM (TELEMATICS TRANSCEIVER))

(a) Connect the I56 radio and display receiver assembly connector.

(b) Connect the T6 map light assembly connector.

(d) Turn the ignition switch to ACC.

(e) Connect an oscilloscope to terminals 6 (MCO+) and 5 (MCO-) of the T6 map light assembly connector.

*a	Component with harness connected (Map Light Assembly)

(f) Check the signal waveform according to the condition(s) in the table below.

Item	Condition
Measurement terminal	T6-6 (MCO+) - T6-5 (MCO-)
Tool setting	50 mV/DIV., 500 ms/DIV.
Vehicle condition	Turn the ignition switch to ACC. Sound is input to the map light assembly when the user is closer than 125 mm from the map light assembly sound holes.

OK:

The waveform is similar to that shown in the illustration.

HINT:

The oscilloscope waveform shown in the illustration is an example for reference only.

GO TO STEP 16

15.	INSPECT DCM (TELEMATICS TRANSCEIVER) (OUTPUT TO RADIO AND DISPLAY RECEIVER ASSEMBLY)

(a) Connect the I56 radio and display receiver assembly connector.

(b) Connect the T6 map light assembly connector.

(d) Turn the ignition switch to ACC.

(e) Connect an oscilloscope to terminals 16 (MCO+) and 32 (MCO-) of the I143 DCM (telematics transceiver) connector.

*a	Component with harness connected (DCM (Telematics Transceiver))

(f) Check the signal waveform according to the condition(s) in the table below.

Item	Condition
Measurement terminal	I143-16 (MCO+) - I143-32 (MCO-)
Tool setting	50 mV/DIV., 500 ms/DIV.
Vehicle condition	Turn the ignition switch to ACC. Sound is input to the map light assembly when the user is closer than 125 mm from the map light assembly sound holes.

OK:

The waveform is similar to that shown in the illustration.

HINT:

The oscilloscope waveform shown in the illustration is an example for reference only.

PROCEED TO NEXT SUSPECTED AREA SHOWN IN PROBLEM SYMPTOMS TABLE

REPLACE DCM (TELEMATICS TRANSCEIVER)

16.	INSPECT MAP LIGHT ASSEMBLY

(a) Remove the map light assembly.

Click here

(b) Disconnect the B telephone microphone assembly connector.

Standard Resistance:

Tester Connection	Condition	Specified Condition
T6-6 (MCO+) - B-3	Always	Below 1 Ω
T6-5 (MCO-) - B-2	Always	Below 1 Ω
T6-6 (MCO+) or B-3 - T6-11 (GND)	Always	10 kΩ or higher
T6-5 (MCO-) or B-2 - T6-11 (GND)	Always	10 kΩ or higher

Component without harness connected

(Map Light Assembly (No. 1 Roof Wire Side))

Component without harness connected

(Map Light Assembly (Telephone Microphone Assembly Side))

REPLACE TELEPHONE MICROPHONE ASSEMBLY

REPLACE MAP LIGHT ASSEMBLY

17.	INSPECT MAP LIGHT ASSEMBLY

(a) Remove the map light assembly.

Click here

(b) Disconnect the B telephone microphone assembly connector.

Standard Resistance:

Tester Connection	Condition	Specified Condition
T6-4 (SNS2) - B-1	Always	Below 1 Ω
T6-5 (MCO-) - B-2	Always	Below 1 Ω
T6-4 (SNS2) or B-1 - T6-11 (GND)	Always	10 kΩ or higher
T6-5 (MCO-) or B-2 - T6-11 (GND)	Always	10 kΩ or higher

Component without harness connected

(Map Light Assembly (No. 1 Roof Wire Side))

Component without harness connected

(Map Light Assembly (Telephone Microphone Assembly Side))

REPLACE TELEPHONE MICROPHONE ASSEMBLY

REPLACE MAP LIGHT ASSEMBLY