DTC B15C4-64: Airbag Signal Plausibility Failure [10/2019 - ]: Procedure

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

   Body Electrical > SRS Airbag > Clear DTCs 

6. Check for DTCs and check that no DTCs are output.

   Body Electrical > SRS Airbag > Trouble Codes 

   OK

   No DTCs are output.

   Result

   Proceed to
   OK
   NG

Result: 

NG 

GO TO AIRBAG SYSTEM. Refer to  DIAGNOSTIC TROUBLE CODE CHART [06/2018 - 08/2021]  , or refer to  DIAGNOSTIC TROUBLE CODE CHART [08/2021 - 09/2022]  , or refer to  DIAGNOSTIC TROUBLE CODE CHART [09/2022 - ] 

Result: 

OK 

See step  2

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

   Body Electrical > Telematics > Clear DTCs 

6. Check for DTCs and check that no DTCs are output.

   Body Electrical > Telematics > Trouble Codes 

   OK

   No DTCs are output.

   Result

   Proceed to
   OK
   NG

Result: 

OK 

USE SIMULATION METHOD TO CHECK. Refer to  HOW TO PROCEED WITH TROUBLESHOOTING [06/2018 - ] 

Result: 

NG 

See step  3

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 [10/2019 - 08/2020] , or refer to REMOVAL [08/2020 - 09/2022] , or refer to REMOVAL [09/2022 - ]

2. Check the input waveform.
   1. Check the signal waveform according to the condition(s) in the table below. (Check the waveform from the back of the wire harness connector of the DCM (telematics transceiver) while the airbag ECU assembly connectors are connected.)

      Reference Waveform

      Item	Condition
      Tester connection	G128-13 (GSW) - Body ground
      Tool setting	5.0 V/DIV., 20 ms/DIV.
      Vehicle condition	Engine switch on (IG)

      OK

      The waveform is similar to that shown in the illustration.

   Result

   Proceed to
   OK
   NG

Result: 

NG 

See step  5

Result: 

OK 

See step  4

1. Replace the DCM (telematics transceiver).

   Refer to REMOVAL [10/2019 - 08/2020] , or refer to REMOVAL [08/2020 - 09/2022] , or refer to REMOVAL [09/2022 - ]

   NOTE:

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

   Result

   Proceed to
   NEXT

Result: 

NEXT 

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

1. Disconnect the G128 DCM (telematics transceiver) connector.
2. Disconnect the G64 airbag ECU assembly connector.
3. Measure the resistance according to the value(s) in the table below.

   Standard Resistance

   Tester Connection	Condition	Specified Condition
   G128-13 (GSW) - G64-23 (GSW3)	Always	Below 1 Ω
   G128-13 (GSW) or G64-23 (GSW3) - Body ground	Always	10 kΩ or higher

   Result

   Proceed to
   OK
   NG

Result: 

OK 

REPLACE AIRBAG ECU ASSEMBLY. Refer to  REMOVAL [06/2018 - 08/2020]  , or refer to  REMOVAL [08/2020 - 08/2021]  , or refer to  REMOVAL [08/2021 - 09/2022]  , or refer to  REMOVAL [09/2022 - ] 

Result: 

NG 

REPAIR OR REPLACE HARNESS OR CONNECTOR