Last Modified: 05-13-2024 6.11:8.1.0 Doc ID: RM100000001LF5L
Model Year Start: 2020 Model: GR Corolla Prod Date Range: [09/2019 - 04/2020]
Title: CELLULAR COMMUNICATION: SAFETY CONNECT SYSTEM (for Sedan, Gasoline Model): B1571; Manual (SOS) Switch Green Indicator Malfunction; 2020 MY Corolla Corolla Hatchback GR Corolla [09/2019 - 04/2020]

DTC

B1571

Manual (SOS) Switch Green Indicator Malfunction

DESCRIPTION

This DTC is set when the DCM (Telematics Transceiver) detects an open or short in the manual (SOS) switch green indicator circuit of the manual (SOS) switch. The manual (SOS) switch green indicator illuminates after the engine switch is turned on (IG).

If the safety connect system is not active, the manual (SOS) switch green indicator will turn off.

If the safety connect system is active, the manual (SOS) switch green indicator will blink while communicating with the call center.

DTC No.

Detection Item

DTC Detection Condition

Trouble Area

B1571

Manual (SOS) Switch Green Indicator Malfunction

Current for manual (SOS) switch green indicator reaches malfunction criteria for 10 seconds when engine switch is on (IG).

  • Map light assembly
  • Wire harness or connector
  • DCM (Telematics Transceiver)

WIRING DIAGRAM

CAUTION / NOTICE / HINT

HINT:

Before performing this diagnostic procedure, make sure to perform Health Check and confirm that the DCM/VIN registration information is correct.

Click here 2020 MY Corolla Corolla Hatchback GR Corolla [09/2019 - 04/2020]; CELLULAR COMMUNICATION: SAFETY CONNECT SYSTEM (for Sedan, Gasoline Model): HEALTH CHECK

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.

(d) Turn the Techstream on.

(e) Clear the DTCs.

Body Electrical > Telematics > Clear DTCs

(f) Recheck for DTCs.

Body Electrical > Telematics > Trouble Codes

Result

Proceed to

DTC B1570, B1571 and B15C5 are output

A

DTC B1571 is output

(DTC B1570 and B15C5 are not output)

B

B

GO TO STEP 5

A

2.

INSPECT MAP LIGHT ASSEMBLY (GREEN INDICATOR)

(a) Disconnect the T6 map light assembly connector.

*a

Component without harness connected

(Map Light Assembly)

(b) Connect 2 dry-cell batteries (1.5 V each) in series.

(c) Connect the positive (+) lead to terminal 19 (IND2) and the negative (-) lead to terminal 12 (GND3) of the map light assembly connector.

(d) Check if the illumination for the manual (SOS) switch green indicator comes on.

OK:

Green indicator comes on.

NG

REPLACE MAP LIGHT ASSEMBLY

OK

3.

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

I72-26 (SIG-) - T6-12 (GND3)

Always

Below 1 Ω

I72-26 (SIG-) or T6-12 (GND3) - Body ground

Always

10 kΩ or higher

I72-12 (IND2) - T6-19 (IND2)

Always

Below 1 Ω

I72-12 (IND2) or T6-19 (IND2) - Body ground

Always

10 kΩ or higher

NG

REPAIR OR REPLACE HARNESS OR CONNECTOR

OK

4.

REPLACE DCM (TELEMATICS TRANSCEIVER)

(a) Replace the DCM (Telematics Transceiver).

Click here 2020 MY Corolla Corolla Hatchback Corolla HV GR Corolla [09/2019 - 04/2020]; CELLULAR COMMUNICATION: DCM(TELEMATICS TRANSCEIVER): REMOVAL

NOTICE:

  • The engine switch must be off.
  • Do not swap the DCM (Telematics Transceiver) with one from another vehicle.
NEXT

PERFORM DCM ACTIVATION

5.

CHECK MAP LIGHT ASSEMBLY (MANUAL (SOS) SWITCH GREEN INDICATOR CONDITION)

(a) Confirm the green indicator status after the engine switch is turned on (IG).

Click here 2020 MY Corolla Corolla Hatchback GR Corolla [09/2019 - 04/2020]; CELLULAR COMMUNICATION: SAFETY CONNECT SYSTEM (for Sedan, Gasoline Model): SYSTEM DESCRIPTION

Result

Proceed to

Green indicator remains off

A

Green indicator remains on

B

B

GO TO STEP 10

A

6.

INSPECT MAP LIGHT ASSEMBLY (GREEN INDICATOR INPUT VOLTAGE)

(a) Remove the map light assembly but do not disconnect the connectors.

Click here 2019 - 2022 MY Corolla Corolla Hatchback Corolla HV GR Corolla [06/2018 - 09/2022]; CELLULAR COMMUNICATION: MANUAL(SOS)SWITCH: REMOVAL

*a

Component with harness connected

(Map Light Assembly)

(b) Connect the positive lead of a voltmeter to terminal T6-19 (IND2), and the negative lead to terminal T6-12 (GND3).

(c) Measure the voltage.

Standard:

1.0 to 8.5 V for 2 seconds after the engine switch is turned on (IG) and red indicator has turned off.

0 V when the engine switch is off.

OK

REPLACE MAP LIGHT ASSEMBLY

NG

7.

INSPECT DCM (TELEMATICS TRANSCEIVER) (GREEN INDICATOR OUTPUT VOLTAGE)

(a) Remove the DCM (Telematics Transceiver) but do not disconnect the connectors.

Click here 2020 MY Corolla Corolla Hatchback Corolla HV GR Corolla [09/2019 - 04/2020]; CELLULAR COMMUNICATION: DCM(TELEMATICS TRANSCEIVER): REMOVAL

*a

Component with harness connected

(DCM (Telematics Transceiver))

(b) Connect the positive lead of a voltmeter to terminal I72-12 (IND2), and the negative lead to body ground.

(c) Measure the voltage.

Standard:

1.0 to 8.5 V for 2 seconds after the engine switch is turned on (IG) and red indicator has turned off.

0 V when the engine switch is off.

OK

REPAIR OR REPLACE HARNESS OR CONNECTOR

NG

8.

CHECK HARNESS AND CONNECTOR (DCM (TELEMATICS TRANSCEIVER) - BODY GROUND)

(a) Remove the DCM (Telematics Transceiver) but do not disconnect the connectors.

Click here 2020 MY Corolla Corolla Hatchback Corolla HV GR Corolla [09/2019 - 04/2020]; CELLULAR COMMUNICATION: DCM(TELEMATICS TRANSCEIVER): REMOVAL

*a

Component with harness connected

(DCM (Telematics Transceiver))

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

Standard Resistance:

Tester Connection

Condition

Specified Condition

I72-12 (IND2) - Body ground

Always

10 kΩ or higher

NG

REPAIR OR REPLACE HARNESS OR CONNECTOR

OK

9.

REPLACE DCM (TELEMATICS TRANSCEIVER)

(a) Replace the DCM (Telematics Transceiver).

Click here 2020 MY Corolla Corolla Hatchback Corolla HV GR Corolla [09/2019 - 04/2020]; CELLULAR COMMUNICATION: DCM(TELEMATICS TRANSCEIVER): REMOVAL

NOTICE:

  • The engine switch must be off.
  • Do not swap the DCM (Telematics Transceiver) with one from another vehicle.
NEXT

PERFORM DCM ACTIVATION

10.

REPLACE DCM (TELEMATICS TRANSCEIVER)

(a) Replace the DCM (Telematics Transceiver).

Click here 2020 MY Corolla Corolla Hatchback Corolla HV GR Corolla [09/2019 - 04/2020]; CELLULAR COMMUNICATION: DCM(TELEMATICS TRANSCEIVER): REMOVAL

NOTICE:

  • The engine switch must be off.
  • Do not swap the DCM (Telematics Transceiver) with one from another vehicle.
NEXT

PERFORM DCM ACTIVATION