DTC B15C4: Airbag Signal Malfunction/Not Input [01/2019 - 04/2020]: Procedure

1. Turn the power switch off.
2. Connect the Techstream to the DLC3.
3. Turn the power switch on (IG) and wait for 10 seconds.
4. Turn the Techstream on.
5. Clear the DTCs.

   Body Electrical > SRS Airbag > Clear DTCs 

6. Recheck for DTCs.

   Body Electrical > SRS Airbag > Trouble Codes 

   Result

   Result	Proceed to
   DTCs are not output	A
   DTCs are output	B

Result: 

B 

GO TO AIRBAG SYSTEM. Refer to  DIAGNOSTIC TROUBLE CODE CHART [01/2019 - 04/2020] 

Result: 

A 

See step  2

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

   Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

   *a	Component with harness connected (DCM (Telematics Transceiver))

   Refer to REMOVAL [01/2019 - 09/2019] , or refer to REMOVAL [09/2019 - 04/2020]

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

   Standard Voltage

   Tester Connection	Condition	Specified Condition
   I72-24 (GSW) - Body ground	Power switch on (IG)	6.5 to 8.5 V

   Reference Waveform

   Item	Condition
   Tester connection	I72-24 (GSW) - Body ground
   Tool setting	5.0 V/DIV., 20 ms/DIV.
   Vehicle condition	Power switch on (IG)

   Result

   Result	Proceed to
   8.5 V or higher	A
   Below 6.5 V	B
   6.5 to 8.5 V	C

Result: 

B 

See step  4

Result: 

C 

See step  5

Result: 

A 

See step  3

1. Remove the airbag sensor assembly but do not disconnect the connectors.

   Refer to REMOVAL [01/2019 - 03/2019] , or refer to REMOVAL [03/2019 - 09/2022]

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

   Standard Voltage

   Tester Connection	Condition	Specified Condition
   I47-23 (GSW3) - Body ground	Power switch on (IG)	8.5 V or higher

   Reference Waveform

   Item	Condition
   Tester connection	I47-23 (GSW3) - Body ground
   Tool setting	5.0 V/DIV., 20 ms/DIV.
   Vehicle condition	Power switch on (IG)

   Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

   *a	Component with harness connected (Airbag Sensor Assembly)

   Result

   Proceed to
   OK
   NG

Result: 

OK 

REPLACE AIRBAG SENSOR ASSEMBLY. Refer to  REMOVAL [01/2019 - 03/2019]  , or refer to  REMOVAL [03/2019 - 09/2022] 

Result: 

NG 

REPAIR OR REPLACE HARNESS OR CONNECTOR 

1. Disconnect the I72 DCM (Telematics Transceiver) connector.
2. Measure the resistance according to the value(s) in the table below.

   Standard Resistance

   Tester Connection	Condition	Specified Condition
   I72-24 (GSW) - Body ground	Always	10 kΩ or higher
   I47-23 (GSW3) - Body ground	Always	10 kΩ or higher

   Result

   Proceed to
   OK
   NG

Result: 

NG 

See step  6

Result: 

OK 

See step  5

1. Replace the DCM (Telematics Transceiver).

   Refer to REMOVAL [01/2019 - 09/2019] , or refer to REMOVAL [09/2019 - 04/2020]

   NOTE:

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

   Result

   Proceed to
   NEXT

Result: 

NEXT 

PERFORM DCM ACTIVATION. Refer to  DCM ACTIVATION [01/2019 - 04/2020] 

1. Disconnect the I72 DCM (Telematics Transceiver) connector.
2. Disconnect the I47 airbag sensor assembly connector.
3. Measure the resistance according to the value(s) in the table below.

   Standard Resistance

   Tester Connection	Condition	Specified Condition
   I72-24 (GSW) - I47-23 (GSW3)	Always	Below 1 Ω
   I72-24 (GSW) or I47-23 (GSW3) - Body ground	Always	10 kΩ or higher

   Result

   Proceed to
   OK
   NG

Result: 

OK 

REPLACE AIRBAG SENSOR ASSEMBLY. Refer to  REMOVAL [01/2019 - 03/2019]  , or refer to  REMOVAL [03/2019 - 09/2022] 

Result: 

NG 

REPAIR OR REPLACE HARNESS OR CONNECTOR