Toyota CH-R Service Manual: Airbag Signal Malfunction/Not Input (B15C4)

Toyota CH-R Service Manual / Cellular Communication / Safety Connect System / Airbag Signal Malfunction/Not Input (B15C4)

DESCRIPTION

If the DCM (Telematics Transceiver) detects an error in communication between the DCM (Telematics Transceiver) and the airbag sensor assembly as a result of the DCM (Telematics Transceiver) self check, this DTC will be set.

DTC No.

Detection Item

DTC Detection Condition

Trouble Area

B15C4

Airbag Signal Malfunction/Not Input

DCM (Telematics Transceiver) detects an error in signals from airbag sensor assembly when ignition switch is ON.
  • Airbag system
  • Wire harness or connector
  • Airbag sensor assembly
  • DCM (Telematics Transceiver)

WIRING DIAGRAM

CAUTION / NOTICE / HINT

NOTICE:

The vehicle is equipped with an SRS (Supplemental Restraint System) which includes components such as airbags. Before servicing (including removal or installation of parts), be sure to read the Precaution in the SRS.

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PROCEDURE

1.

CHECK DTC (AIRBAG SYSTEM)

(a) Turn the ignition switch off.

(b) Connect the Techstream to the DLC3.

(c) Turn the ignition switch ON and wait for 10 seconds.

(d) Turn the Techstream on.

(e) Clear the DTCs.

Body Electrical > SRS Airbag > Clear DTCs

(f) Recheck for DTCs.

Body Electrical > SRS Airbag > Trouble Codes

Result

Proceed to

DTCs are not output

A

DTCs are output

B
B

GO TO AIRBAG SYSTEM

A

2.

INSPECT DCM (TELEMATICS TRANSCEIVER) (GSW SIGNAL)

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

Click here

*a

Component with harness connected

(DCM (Telematics Transceiver))

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

Standard Voltage:

Tester Connection

Switch Condition

Specified Condition

F134-24 (GSW) - Body ground

Ignition switch ON

6.5 to 8.5 V

Reference Waveform:

Item

Condition

Tester connection

F134-24 (GSW) - Body ground

Tool setting

5.0 V/DIV., 20 ms/DIV.

Vehicle condition

Ignition switch ON

Result

Proceed to

8.5 V or higher

A

Below 6.5 V

B

6.5 to 8.5 V

C
B

GO TO STEP 4

C

GO TO STEP 5

A

3.

CHECK HARNESS AND CONNECTOR (FOR OPEN CIRCUIT)

(a) Remove the airbag sensor assembly but do not disconnect the connectors.

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

Standard Voltage:

Tester Connection

Switch Condition

Specified Condition

F70-24 (GSW3) - Body ground

Ignition switch ON

8.5 V or higher

Reference Waveform:

Item

Condition

Tester connection

F70-24 (GSW3) - Body ground

Tool setting

5.0 V/DIV., 20 ms/DIV.

Vehicle condition

Ignition switch ON

*a

Component with harness connected

(Airbag Sensor Assembly)
OK

REPLACE AIRBAG SENSOR ASSEMBLY

NG

REPAIR OR REPLACE HARNESS OR CONNECTOR

4.

CHECK HARNESS AND CONNECTOR (FOR SHORT CIRCUIT)

(a) Disconnect the F134 DCM (Telematics Transceiver) connector.

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

Standard Resistance:

Tester Connection

Condition

Specified Condition

F134-24 (GSW) - Body ground

Always

10 kΩ or higher

F70-24 (GSW3) - Body ground

Always

10 kΩ or higher
NG

GO TO STEP 6

OK

5.

REPLACE DCM (TELEMATICS TRANSCEIVER)

(a) Replace the DCM (Telematics Transceiver).

Click here

NOTICE:

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

PERFORM DCM ACTIVATION

6.

CHECK HARNESS AND CONNECTOR (DCM (TELEMATICS TRANSCEIVER) - AIRBAG SENSOR ASSEMBLY)

(a) Disconnect the F134 DCM (Telematics Transceiver) connector.

(b) Disconnect the F70 airbag sensor assembly connector.

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

Standard Resistance:

Tester Connection

Condition

Specified Condition

F134-24 (GSW) - F70-24 (GSW3)

Always

Below 1 Ω

F134-24 (GSW) or F70-24 (GSW3) - Body ground

Always

10 kΩ or higher
OK

REPLACE AIRBAG SENSOR ASSEMBLY

NG

REPAIR OR REPLACE HARNESS OR CONNECTOR
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