Last Modified: 05-13-2024 6.11:8.1.0 Doc ID: RM1000000028I7S
Model Year Start: 2023 Model: GR Corolla Prod Date Range: [11/2022 -           ]
Title: CELLULAR COMMUNICATION: SAFETY CONNECT SYSTEM (for Gasoline Model): B157213; Microphone Circuit Open; 2023 - 2025 MY Corolla Corolla Hatchback GR Corolla [11/2022 -        ]

DTC

B157213

Microphone Circuit Open

DESCRIPTION

This DTC is stored when the DCM (telematics transceiver) detects a malfunction in the telephone microphone assembly circuit.

DTC No.

Detection Item

DTC Detection Condition

Trouble Area

B157213

Microphone Circuit Open

Current at terminal MCVD is lower than the malfunction threshold for 10 seconds or more while the engine switch is on (IG)
  • DCM (telematics transceiver)
  • Telephone microphone assembly LH
  • Harness or connector

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 Safety Connect System.

Click here 2023 - 2025 MY Corolla Corolla Hatchback GR Corolla [09/2022 -        ]; CELLULAR COMMUNICATION: SAFETY CONNECT SYSTEM (for Gasoline Model): PRECAUTION

PROCEDURE

1.

CHECK DTC

(a) Turn the engine switch off.

(b) Connect the Techstream to the DLC3.

(c) Turn the engine switch on (IG) and wait for 10 seconds or more.

(d) Turn the Techstream on.

(e) Clear the DTCs.

Body Electrical > Telematics > Clear DTCs

(f) Check for DTCs and check that no DTCs are output.

Body Electrical > Telematics > Trouble Codes

OK:

No DTCs are output.

OK

USE SIMULATION METHOD TO CHECK

NG

2.

CHECK HARNESS AND CONNECTOR (DCM (TELEMATICS TRANSCEIVER) - TELEPHONE MICROPHONE ASSEMBLY LH)

(a) Disconnect the I143 telematics transceiver connector.

(b) Disconnect the T24 telephone microphone assembly LH connector.

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

Standard Resistance:

Tester Connection

Condition

Specified Condition

I143-5 (MCVD) - T24-1 (MAC1)

Always

Below 1 Ω

I143-6 (MCI+) - T24-2 (MO1+)

Always

Below 1 Ω

I143-7 (MCI-) - T24-4 (MO1-)

Always

Below 1 Ω

I143-23 (SGND) - Body ground

Always

10 kΩ or higher

I143-5 (MCVD) or T24-1 (MAC1) - Body ground

Always

10 kΩ or higher

I143-6 (MCI+) or T24-2 (MO1+) - Body ground

Always

10 kΩ or higher

I143-7 (MCI-) or T24-4 (MO1-) - Body ground

Always

10 kΩ or higher
NG

REPAIR OR REPLACE HARNESS OR CONNECTOR
OK

3.

CHECK DCM (TELEMATICS TRANSCEIVER) (TELEPHONE MICROPHONE ASSEMBLY LH POWER SOURCE)

(a) Remove the telephone microphone assembly LH but do not disconnect the connectors.

Click here 2023 - 2025 MY Corolla Corolla Hatchback Corolla HV GR Corolla [11/2022 -        ]; AUDIO / VIDEO: MICROPHONE: REMOVAL

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

Standard Voltage:

Tester Connection

Switch Condition

Specified Condition

T24-1 (MAC1) - Body ground

Engine switch on (IG)

7.5 to 8.5 V

Standard Resistance:

Tester Connection

Condition

Specified Condition

T24-4 (MO1-) - Body ground

Always

Below 1 Ω

*a

Component with harness connected

(Telephone Microphone Assembly LH)
OK

REPLACE TELEPHONE MICROPHONE ASSEMBLY LH

NG

4.

REPLACE DCM (TELEMATICS TRANSCEIVER)

(a) Replace the DCM (telematics transceiver) with a new one.

Click here 2023 - 2025 MY Corolla Corolla Hatchback Corolla HV GR Corolla [11/2022 -        ]; CELLULAR COMMUNICATION: DCM(TELEMATICS TRANSCEIVER): REMOVAL

NOTICE:

  • The engine switch must be off.
  • Do not exchange the DCM (telematics transceiver) with one from another vehicle.
NEXT

PERFORM DCM ACTIVATION