Last Modified: 05-13-2024 6.11:8.1.0 Doc ID: RM100000001KREM
Model Year Start: 2020 Model: GR Corolla Prod Date Range: [09/2019 - 04/2020]
Title: NAVIGATION / MULTI INFO DISPLAY: NAVIGATION SYSTEM: Mute Signal Circuit between Radio Receiver and Telematics Transceiver; 2020 MY Corolla Corolla Hatchback Corolla HV GR Corolla [09/2019 - 04/2020]

Mute Signal Circuit between Radio Receiver and Telematics Transceiver

DESCRIPTION

The DCM (telematics transceiver) sends a mute signal to the radio and display receiver assembly.

The radio and display receiver assembly controls the volume according to the mute signal from the DCM (telematics transceiver).

WIRING DIAGRAM

for Hatchback Model
for Sedan Model

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 Navigation System.

    Click here 2020 - 2022 MY Corolla Corolla Hatchback Corolla HV GR Corolla [03/2019 - 09/2022]; NAVIGATION / MULTI INFO DISPLAY: NAVIGATION SYSTEM: 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 [09/2019 - 04/2020]; THEFT DETERRENT / KEYLESS ENTRY: SMART KEY SYSTEM (for Start Function, Gasoline Model): REGISTRATION

PROCEDURE

1.

CHECK MODEL

(a) Choose the model to be inspected.

Result

Proceed to

for Hatchback Model

A

for Sedan Model

B

B

GO TO STEP 5

A

2.

INSPECT DCM (TELEMATICS TRANSCEIVER)

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

Standard Voltage:

Tester Connection

Condition

Specified Condition

I143-14 (MUTE) - Body ground

Ignition switch ACC

Audio system playing

→ Emergency call mode

2.0 V or higher

→ Below 1 V

*a

Component with harness connected

(DCM (Telematics Transceiver))

OK

PROCEED TO NEXT SUSPECTED AREA SHOWN IN PROBLEM SYMPTOMS TABLE

NG

3.

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.

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

Standard Resistance:

Tester Connection

Condition

Specified Condition

I56-3 (TMUT) - I143-14 (MUTE)

Always

Below 1 Ω

I56-3 (TMUT) or I143-14 (MUTE) - Body ground

Always

10 kΩ or higher

NG

REPAIR OR REPLACE HARNESS OR CONNECTOR

OK

4.

INSPECT RADIO AND DISPLAY RECEIVER ASSEMBLY

(a) Disconnect 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

I143-14 (MUTE) - Body ground

Ignition switch ACC

2.0 V or higher

*a

Front view of wire harness connector

(to DCM (Telematics Transceiver))

OK

REPLACE DCM (TELEMATICS TRANSCEIVER)

NG

REPLACE RADIO AND DISPLAY RECEIVER ASSEMBLY

5.

INSPECT DCM (TELEMATICS TRANSCEIVER)

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

Standard Voltage:

Tester Connection

Condition

Specified Condition

I72-17 (MUTE) - Body ground

Ignition switch ACC

Audio system playing

→ Emergency call mode

2.0 V or higher

→ Below 1 V

*a

Component with harness connected

(DCM (Telematics Transceiver))

OK

PROCEED TO NEXT SUSPECTED AREA SHOWN IN PROBLEM SYMPTOMS TABLE

NG

6.

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

I56-3 (TMUT) - I72-17 (MUTE)

Always

Below 1 Ω

I56-3 (TMUT) or I72-17 (MUTE) - Body ground

Always

10 kΩ or higher

NG

REPAIR OR REPLACE HARNESS OR CONNECTOR

OK

7.

INSPECT RADIO AND DISPLAY RECEIVER ASSEMBLY

(a) Disconnect 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

I72-17 (MUTE) - Body ground

Ignition switch ACC

2.0 V or higher

*a

Front view of wire harness connector

(to DCM (Telematics Transceiver))

OK

REPLACE DCM (TELEMATICS TRANSCEIVER)

NG

REPLACE RADIO AND DISPLAY RECEIVER ASSEMBLY