DTC B15C4-64: Airbag Signal Signal Plausibility Failure [10/2019 - 07/2022]: 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 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 [10/2018 - 10/2020]  , or refer to  DIAGNOSTIC TROUBLE CODE CHART [10/2020 - 08/2021]  , or refer to  DIAGNOSTIC TROUBLE CODE CHART [08/2021 - 07/2022] 

Result: 

OK 

See step  2

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 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 [10/2018 - ] 

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 - 07/2022]

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 sensor assembly connectors are connected.)

      Reference Waveform

      Item	Condition
      Tester connection	F126-13 (GSW) - Body ground
      Tool setting	5.0 V/DIV., 20 ms/DIV.
      Vehicle condition	Ignition switch ON

      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 - 07/2022]

   NOTE:

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

   Result

   Proceed to
   NEXT

Result: 

NEXT 

PERFORM DCM (TELEMATICS TRANSCEIVER) ACTIVATION. Refer to  DCM ACTIVATION [10/2019 - 07/2022] 

1. Disconnect the F126 DCM (telematics transceiver) connector.
2. Disconnect the 4A instrument panel junction block assembly connector.
3. Measure the resistance according to the value(s) in the table below.

   Standard Resistance

   Tester Connection	Condition	Specified Condition
   F126-13 (GSW) - 4A-28	Always	Below 1 Ω
   F126-13 (GSW) or 4A-28 - Body ground	Always	10 kΩ or higher

   Result

   Proceed to
   OK
   NG

Result: 

NG 

REPAIR OR REPLACE HARNESS OR CONNECTOR 

Result: 

OK 

See step  6

1. Disconnect the 4A instrument panel junction block assembly connector.
2. Disconnect the F57 airbag ECU assembly connector.
3. Measure the resistance according to the value(s) in the table below.

   Standard Resistance

   Tester Connection	Condition	Specified Condition
   4A-25 - F57-23 (GSW3)	Always	Below 1 Ω
   4A-25 or F57-23 (GSW3) - Body ground	Always	10 kΩ or higher

   Result

   Proceed to
   OK
   NG

Result: 

OK 

REPLACE INSTRUMENT PANEL JUNCTION BLOCK ASSEMBLY. Refer to  REMOVAL [10/2018 - 07/2022] 

Result: 

NG 

REPAIR OR REPLACE HARNESS OR CONNECTOR