DTC B15C4: Airbag Signal Malfunction/Not Input [11/2018 - 10/2019]: Procedure

1. Turn the ignition switch off.
2. Connect the Techstream to the DLC3.
3. Turn the ignition switch to ON and wait for 10 seconds.
4. Turn the Techstream on.
5. Clear the DTCs.

   Refer to DTC CHECK / CLEAR [11/2018 - 08/2020]

   Body Electrical > SRS Airbag > Clear DTCs 

6. Recheck for DTCs.

   Refer to DTC CHECK / CLEAR [11/2018 - 08/2020]

   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 [11/2018 - 02/2019]  , or refer to  DIAGNOSTIC TROUBLE CODE CHART [02/2019 - 08/2020] 

Result: 

A 

See step  2

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

   Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

   *a	Component with harness connected (DCM (Telephone Transceiver Assembly))

   Refer to REMOVAL [11/2018 - 10/2019]

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

   Standard Voltage

   Tester Connection	Switch Condition	Specified Condition
   G9-24 (GSW) - Body ground	Ignition switch ON	6.5 to 8.5 V

   Reference Waveform

   Item	Condition
   Tester connection	G9-24 (GSW) - Body ground
   Tool setting	5.0 V/DIV., 20 ms/DIV.
   Vehicle condition	Ignition switch ON

   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 ECU assembly but do not disconnect the connectors.

   Refer to REMOVAL [11/2018 - 02/2019] , or refer to REMOVAL [02/2019 - 10/2019]

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

   Standard Voltage

   Tester Connection	Switch Condition	Specified Condition
   G70-23 (GSW3) - Body ground	Ignition switch ON	8.5 V or higher

   Reference Waveform

   Item	Condition
   Tester connection	G70-23 (GSW3) - Body ground
   Tool setting	5.0 V/DIV., 20 ms/DIV.
   Vehicle condition	Ignition switch ON

   Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

   *a	Component with harness connected (Airbag ECU Assembly)

   Result

   Proceed to
   OK
   NG

Result: 

OK 

REPLACE AIRBAG ECU ASSEMBLY. Refer to  REMOVAL [11/2018 - 02/2019]  , or refer to  REMOVAL [02/2019 - 10/2019] 

Result: 

NG 

REPAIR OR REPLACE HARNESS OR CONNECTOR 

1. Disconnect the G9 DCM (Telephone Transceiver Assembly) connector.
2. Disconnect the G70 airbag ECU assembly connector.
3. Measure the resistance according to the value(s) in the table below.

   Standard Resistance

   Tester Connection	Condition	Specified Condition
   G9-24 (GSW) - Body ground	Always	10 kΩ or higher
   G70-23 (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 (Telephone Transceiver Assembly).

   Refer to REMOVAL [11/2018 - 10/2019]

   NOTE:

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

   Result

   Proceed to
   NEXT

Result: 

NEXT 

PERFORM DCM ACTIVATION. Refer to  DCM ACTIVATION [11/2018 - 10/2019] 

1. Disconnect the G9 DCM (Telephone Transceiver Assembly) connector.
2. Disconnect the G70 airbag ECU assembly connector.
3. Measure the resistance according to the value(s) in the table below.

   Standard Resistance

   Tester Connection	Condition	Specified Condition
   G9-24 (GSW) - G70-23 (GSW3)	Always	Below 1 Ω
   G9-24 (GSW) or G70-23 (GSW3) - Body ground	Always	10 kΩ or higher

   Result

   Proceed to
   OK
   NG

Result: 

OK 

REPLACE AIRBAG ECU ASSEMBLY. Refer to  REMOVAL [11/2018 - 02/2019]  , or refer to  REMOVAL [02/2019 - 10/2019] 

Result: 

NG 

REPAIR OR REPLACE HARNESS OR CONNECTOR