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Home >> Lexus >> 2020 >> LS 500h AWD >> Repair and Diagnosis (Single Page) >> Accessories & Equipment >> Entertainment Systems >> Safety Connect System - Diagnostic Codes (2 Of 2) & Symptom Tests >> Safety Connect System >> DTC B15C4: Airbag Signal Malfunction/Not Input [10/2017 - 10/2020] >> Procedure

DTC B15C4: Airbag Signal Malfunction/Not Input [10/2017 - 10/2020]: Procedure

  1. CHECK DTC (AIRBAG SYSTEM) 
    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. Check the DTC of "AIRBAG SYSTEM".

      Refer to DTC CHECK / CLEAR [10/2017 - 10/2020]

      Result

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

    Result: 

    GO TO AIRBAG SYSTEM. Refer to  DIAGNOSTIC TROUBLE CODE CHART [10/2017 - 09/2018]  , or refer to  DIAGNOSTIC TROUBLE CODE CHART [09/2018 - 10/2020] 

    Result: 

    See step  2

  2. CHECK DCM (TELEMATICS TRANSCEIVER) (GSW SIGNAL) 
    1. Remove the DCM (Telematics Transceiver) but do not disconnect the connectors.
      GTY800173Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
      *a Component with harness connected
      (DCM [Telematics Transceiver])

      Refer to REMOVAL [10/2017 - 09/2018] , or refer to REMOVAL [09/2018 - 10/2020]

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

      Standard Voltage

      Tester Connection Switch Condition Specified Condition
      G56-24 (GSW) - Body ground Power switch on (IG) Pulse generation

      Reference Waveform

      Item Condition
      Tester Connection G56-24 (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
      Pulse generation C

    Result: 

    See step  4

    Result: 

    See step  6

    Result: 

    See step  3

  3. CHECK HARNESS AND CONNECTOR (DCM [TELEMATICS TRANSCEIVER] - AIRBAG ECU ASSEMBLY) 
    1. Disconnect the G56 DCM (Telematics Transceiver) connector.
    2. Disconnect the G11 airbag ECU assembly connector.
    3. Measure the resistance according to the value(s) in the table below.

      Standard Resistance

      Tester Connection Condition Specified Condition
      G56-24 (GSW) - G11-23 (GSW3) Always Below 1 Ω
      G56-24 (GSW) - Body ground Always 10 kΩ or higher
      G11-23 (GSW3) - Body ground Always 10 kΩ or higher

      Result

      Proceed to
      OK
      NG

    Result: 

    OK 

    REPLACE AIRBAG ECU ASSEMBLY. Refer to  REMOVAL [10/2017 - 09/2018]  , or refer to  REMOVAL [09/2018 - 10/2020] 

    Result: 

    NG 

    REPAIR OR REPLACE HARNESS OR CONNECTOR 

  4. CHECK HARNESS AND CONNECTOR (FOR SHORT CIRCUIT) 
    1. Disconnect the G56 DCM (Telematics Transceiver) connector.
    2. Disconnect the G11 airbag ECU assembly connector.
    3. Measure the resistance according to the value(s) in the table below.

      Standard Resistance

      Tester Connection Condition Specified Condition
      G56-24 (GSW) - Body ground Always 10 kΩ or higher
      G11-23 (GSW3) - Body ground Always 10 kΩ or higher

      Result

      Proceed to
      OK
      NG

    Result: 

    NG 

    REPAIR OR REPLACE HARNESS OR CONNECTOR 

    Result: 

    OK 

    See step  5

  5. CHECK DCM (TELEMATICS TRANSCEIVER) 
    1. Remove the airbag ECU assembly disconnect the connectors.

      Refer to REMOVAL [10/2017 - 09/2018] , or refer to REMOVAL [09/2018 - 10/2020]

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

      Standard Voltage

      Tester Connection Switch Condition Specified Condition
      G56-24 (GSW) - Body ground Power switch on (IG) 8.5 V or higher
      GTY826433Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
      *a Component with harness connected
      (DCM [Telematics Transceiver])

      Result

      Proceed to
      OK
      NG

    Result: 

    OK 

    REPLACE AIRBAG ECU ASSEMBLY. Refer to  REMOVAL [10/2017 - 09/2018]  , or refer to  REMOVAL [09/2018 - 10/2020] 

    Result: 

    NG 

    See step  6

  6. REPLACE TELEMATICS TRANSCEIVER 
    1. Replace the DCM (Telematics Transceiver).

      Refer to REMOVAL [10/2017 - 09/2018] , or refer to REMOVAL [09/2018 - 10/2020]

      NOTE:
      • The power 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 [10/2017 - 10/2020]