Last Modified: 05-13-2024 6.11:8.1.0 Doc ID: RM100000001GWL4
Model Year Start: 2020 Model: GR Corolla Prod Date Range: [01/2019 - 09/2019]
Title: AUDIO / VIDEO: AUDIO AND VISUAL SYSTEM (for Gasoline Model with Dual Knob Type): Microphone Circuit; 2020 MY Corolla Corolla Hatchback GR Corolla [01/2019 - 09/2019]

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 2020 - 2022 MY Corolla Corolla Hatchback GR Corolla [01/2019 - 09/2022]; AUDIO / VIDEO: AUDIO AND VISUAL SYSTEM (for Gasoline Model with Dual Knob Type): PRECAUTION

  • 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 2020 MY Corolla Corolla Hatchback GR Corolla [01/2019 - 09/2019]; THEFT DETERRENT / KEYLESS ENTRY: SMART KEY SYSTEM (for Start Function, Gasoline Model): REGISTRATION

PROCEDURE

1.

CHECK MICROPHONE (OPERATION CHECK)

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

Click here 2020 MY Corolla Corolla Hatchback GR Corolla [01/2019 - 09/2019]; AUDIO / VIDEO: AUDIO AND VISUAL SYSTEM (for Gasoline Model with Dual Knob Type): OPERATION CHECK

(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
B

GO TO STEP 8

C

REPLACE RADIO AND DISPLAY RECEIVER ASSEMBLY 2020 MY Corolla Corolla Hatchback Corolla HV GR Corolla [01/2019 - 03/2019]; AUDIO / VIDEO: RADIO RECEIVER: REMOVAL 2020 - 2022 MY Corolla Corolla Hatchback Corolla HV GR Corolla [03/2019 - 09/2022]; AUDIO / VIDEO: RADIO RECEIVER: REMOVAL

A

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.

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

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
NG

REPAIR OR REPLACE HARNESS OR CONNECTOR
OK

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.

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

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
NG

REPLACE RADIO AND DISPLAY RECEIVER ASSEMBLY 2020 MY Corolla Corolla Hatchback Corolla HV GR Corolla [01/2019 - 03/2019]; AUDIO / VIDEO: RADIO RECEIVER: REMOVAL 2020 - 2022 MY Corolla Corolla Hatchback Corolla HV GR Corolla [03/2019 - 09/2022]; AUDIO / VIDEO: RADIO RECEIVER: REMOVAL

OK

4.

INSPECT MAP LIGHT ASSEMBLY

(a) Remove the map light assembly.

Click here 2020 - 2022 MY Corolla Corolla Hatchback Corolla HV GR Corolla [01/2019 - 09/2022]; LIGHTING (INT): PERSONAL LIGHT: REMOVAL

(b) Connect the B telephone microphone assembly connector.

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

Standard Resistance:

Tester Connection

Condition

Specified Condition

4 (SNS2) - 5 (MCO-)

Always

Below 1 Ω

*a

Component without harness connected

(Map Light Assembly)
NG

GO TO STEP 7

OK

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.

(c) Turn the ignition switch to ACC.

(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
  1. Turn the ignition switch to ACC.
  2. 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.

OK

PROCEED TO NEXT SUSPECTED AREA SHOWN IN PROBLEM SYMPTOMS TABLE

NG

6.

INSPECT MAP LIGHT ASSEMBLY

(a) Remove the map light assembly.

Click here 2020 - 2022 MY Corolla Corolla Hatchback Corolla HV GR Corolla [01/2019 - 09/2022]; LIGHTING (INT): PERSONAL LIGHT: REMOVAL

(b) Disconnect the B telephone microphone assembly connector.

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

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

*a

Component without harness connected

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

*b

Component without harness connected

(Map Light Assembly (Telephone Microphone Assembly Side))
OK

REPLACE TELEPHONE MICROPHONE ASSEMBLY

NG

REPLACE MAP LIGHT ASSEMBLY

7.

INSPECT MAP LIGHT ASSEMBLY

(a) Remove the map light assembly.

Click here 2020 - 2022 MY Corolla Corolla Hatchback Corolla HV GR Corolla [01/2019 - 09/2022]; LIGHTING (INT): PERSONAL LIGHT: REMOVAL

(b) Disconnect the B telephone microphone assembly connector.

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

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

*a

Component without harness connected

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

*b

Component without harness connected

(Map Light Assembly (Telephone Microphone Assembly Side))
OK

REPLACE TELEPHONE MICROPHONE ASSEMBLY

NG

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.

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

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
NG

REPAIR OR REPLACE HARNESS OR CONNECTOR
OK

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 I72 DCM (telematics transceiver) connector.

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

Standard Resistance:

Tester Connection

Condition

Specified Condition

I56-21 (MIN+) - I72-18 (MCO+)

Always

Below 1 Ω

I56-22 (MIN-) - I72-19 (MCO-)

Always

Below 1 Ω

I56-21 (MIN+) or I72-18 (MCO+) - Body ground

Always

10 kΩ or higher

I56-22 (MIN-) or I72-19 (MCO-) - Body ground

Always

10 kΩ or higher

I56-24 (SGND) - Body ground

Always

10 kΩ or higher
NG

REPAIR OR REPLACE HARNESS OR CONNECTOR
OK

10.

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

(a) Disconnect the I72 DCM (telematics transceiver) connector.

(b) Disconnect the T6 map light assembly connector.

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

Standard Resistance:

Tester Connection

Condition

Specified Condition

I72-33 (MCVD) - T6-7 (MACC)

Always

Below 1 Ω

I72-34 (MCI+) - T6-6 (MCO+)

Always

Below 1 Ω

I72-35 (MCI-) - T6-5 (MCO-)

Always

Below 1 Ω

I72-33 (MCVD) or T6-7 (MACC) - Body ground

Always

10 kΩ or higher

I72-34 (MCI+) or T6-6 (MCO+) - Body ground

Always

10 kΩ or higher

I72-35 (MCI-) or T6-5 (MCO-) - Body ground

Always

10 kΩ or higher

I72-32 (SGND) - Body ground

Always

10 kΩ or higher
NG

REPAIR OR REPLACE HARNESS OR CONNECTOR
OK

11.

INSPECT RADIO AND DISPLAY RECEIVER ASSEMBLY

(a) Disconnect the I72 DCM (telematics transceiver) connector.

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

*a

Component with harness connected

(Radio and Display Receiver Assembly)

(c) 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
NG

REPLACE RADIO AND DISPLAY RECEIVER ASSEMBLY 2020 MY Corolla Corolla Hatchback Corolla HV GR Corolla [01/2019 - 03/2019]; AUDIO / VIDEO: RADIO RECEIVER: REMOVAL 2020 - 2022 MY Corolla Corolla Hatchback Corolla HV GR Corolla [03/2019 - 09/2022]; AUDIO / VIDEO: RADIO RECEIVER: REMOVAL

OK

12.

INSPECT DCM (TELEMATICS TRANSCEIVER)

(a) Connect the I72 DCM (telematics transceiver) connector.

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

Standard Voltage:

Tester Connection

Condition

Specified Condition

I72-33 (MCVD) - Body ground

Ignition switch ACC

4 to 6 V

*a

Component with harness connected

(DCM (Telematics Transceiver))

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

Standard Resistance:

Tester Connection

Condition

Specified Condition

I72-35 (MCI-) - Body ground

Always

Below 1 Ω

I72-32 (SGND) - Body ground

Always

Below 1 Ω
NG

REPLACE DCM (TELEMATICS TRANSCEIVER)

OK

13.

INSPECT MAP LIGHT ASSEMBLY

(a) Remove the map light assembly.

Click here 2020 - 2022 MY Corolla Corolla Hatchback Corolla HV GR Corolla [01/2019 - 09/2022]; LIGHTING (INT): PERSONAL LIGHT: REMOVAL

(b) Connect the B telephone microphone assembly connector.

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

Standard Resistance:

Tester Connection

Condition

Specified Condition

4 (SNS2) - 5 (MCO-)

Always

Below 1 Ω

*a

Component without harness connected

(Map Light Assembly)
NG

GO TO STEP 17

OK

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.

(c) Connect the I72 DCM (telematics transceiver) 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
  1. Turn the ignition switch to ACC.
  2. 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.

NG

GO TO STEP 16

OK

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.

(c) Connect the I72 DCM (telematics transceiver) connector.

(d) Turn the ignition switch to ACC.

(e) Connect an oscilloscope to terminals 18 (MCO+) and 19 (MCO-) of the I72 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

I72-18 (MCO+) - I72-19 (MCO-)

Tool setting

50 mV/DIV., 500 ms/DIV.

Vehicle condition
  1. Turn the ignition switch to ACC.
  2. 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.

OK

PROCEED TO NEXT SUSPECTED AREA SHOWN IN PROBLEM SYMPTOMS TABLE

NG

REPLACE DCM (TELEMATICS TRANSCEIVER)

16.

INSPECT MAP LIGHT ASSEMBLY

(a) Remove the map light assembly.

Click here 2020 - 2022 MY Corolla Corolla Hatchback Corolla HV GR Corolla [01/2019 - 09/2022]; LIGHTING (INT): PERSONAL LIGHT: REMOVAL

(b) Disconnect the B telephone microphone assembly connector.

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

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

*a

Component without harness connected

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

*b

Component without harness connected

(Map Light Assembly (Telephone Microphone Assembly Side))
OK

REPLACE TELEPHONE MICROPHONE ASSEMBLY

NG

REPLACE MAP LIGHT ASSEMBLY

17.

INSPECT MAP LIGHT ASSEMBLY

(a) Remove the map light assembly.

Click here 2020 - 2022 MY Corolla Corolla Hatchback Corolla HV GR Corolla [01/2019 - 09/2022]; LIGHTING (INT): PERSONAL LIGHT: REMOVAL

(b) Disconnect the B telephone microphone assembly connector.

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

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

*a

Component without harness connected

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

*b

Component without harness connected

(Map Light Assembly (Telephone Microphone Assembly Side))
OK

REPLACE TELEPHONE MICROPHONE ASSEMBLY

NG

REPLACE MAP LIGHT ASSEMBLY