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Home >> Lexus >> 2024 >> ES 350 Base >> Repair and Diagnosis >> Restraints >> Air Bag, SRS >> Airbag System (Except Hybrid) - Diagnostic Codes (2 Of 3) >> AIRBAG SYSTEM (for Gasoline Model) >> DTC B1647: Side Satellite Sensor Bus Lost Communication (LH); DTC B1648: Side Satellite Sensor Bus Initialization Error (LH) [06/2018 - 09/2022] >> Procedure

DTC B1647: Side Satellite Sensor Bus Lost Communication (LH); DTC B1648: Side Satellite Sensor Bus Initialization Error (LH) [06/2018 - 09/2022]: Procedure

  1. CHECK CONNECTION OF CONNECTORS 
    1. Turn the engine switch off.
    2. Disconnect the cable from the negative (-) battery terminal.
      WARNING:

      Wait at least 90 seconds after disconnecting the cable from the negative (-) battery terminal to disable the SRS system.

    3. Check that the connectors are properly connected to the airbag ECU assembly, door side airbag sensor LH and side No. 2 airbag sensor assembly LH. Also check that the connectors that link the floor wire and front door wire LH are properly connected.

      OK

      The connectors are properly connected.

      Result

      Proceed to
      OK
      NG

    Result: 

    NG 

    CONNECT CONNECTORS PROPERLY 

    Result: 

    OK 

    See step  2

  2. CHECK CONNECTORS 
    1. Disconnect the connectors from the airbag ECU assembly, door side airbag sensor LH and side No. 2 airbag sensor assembly LH. Also disconnect the connectors that link the floor wire and front door wire LH.
    2. Check that the terminals of the connectors are not deformed or damaged.

      OK

      The terminals are not deformed or damaged.

      Result

      Proceed to
      OK
      NG

    Result: 

    NG 

    REPLACE FLOOR WIRE OR FRONT DOOR WIRE LH 

    Result: 

    OK 

    See step  3

  3. CHECK FLOOR WIRE 
    1. Connect the cable to the negative (-) battery terminal.
      GTY830194Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
      *1 Side No. 2 Airbag Sensor Assembly LH
      *2 Airbag ECU Assembly
      *3 Floor Wire
      *4 Service Wire
      *a Front view of wire harness connector
      (to Airbag ECU Assembly)
      *b Front view of wire harness connector
      (to Side No. 2 Airbag Sensor Assembly LH)
    2. Turn the engine switch on (IG).
    3. Measure the voltage according to the value(s) in the table below.

      Standard Voltage

      Tester Connection Condition Specified Condition
      N36-4 (BCL+) - Body ground Engine switch on (IG) Below 1 V
      N36-3 (BCL-) - Body ground Engine switch on (IG) Below 1 V
    4. Turn the engine switch off.
    5. Disconnect the cable from the negative (-) battery terminal.
      WARNING:

      Wait at least 90 seconds after disconnecting the cable from the negative (-) battery terminal to disable the SRS system.

    6. Using a service wire, connect terminals 32 (BBL+) and 31 (BBL-) of connector B.
      NOTE:

      Do not forcibly insert the service wire into the terminals of the connector when connecting the wire.

    7. Measure the resistance according to the value(s) in the table below.

      Standard Resistance

      Tester Connection Condition Specified Condition
      N36-4 (BCL+) - N36-3 (BCL-) Always Below 1 Ω
    8. Disconnect the service wire from connector B.
    9. Measure the resistance according to the value(s) in the table below.

      Standard Resistance

      Tester Connection Condition Specified Condition
      N36-4 (BCL+) - N36-3 (BCL-) Always 1 MΩ or higher
      N36-4 (BCL+) - Body ground Always 1 MΩ or higher
      N36-3 (BCL-) - Body ground Always 1 MΩ or higher

      Result

      Proceed to
      OK
      NG

    Result: 

    NG 

    REPLACE FLOOR WIRE 

    Result: 

    OK 

    See step  4

  4. CHECK WIRE HARNESS 
    1. Connect the connectors that link the floor wire and front door wire LH.
      GTY793108Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
      *1 Door Side Airbag Sensor LH
      *2 Side No. 2 Airbag Sensor Assembly LH
      *3 Front Door Wire LH
      *4 Floor Wire
      *5 Service Wire
      *a Front view of wire harness connector
      (to Side No. 2 Airbag Sensor Assembly LH)
      *b Front view of wire harness connector
      (to Door Side Airbag Sensor LH)
    2. Connect the cable to the negative (-) battery terminal.
    3. Turn the engine switch on (IG).
    4. Measure the voltage according to the value(s) in the table below.

      Standard Voltage

      Tester Connection Condition Specified Condition
      N36-1 (BDL+) - Body ground Engine switch on (IG) Below 1 V
      N36-2 (BDL-) - Body ground Engine switch on (IG) Below 1 V
    5. Turn the engine switch off.
    6. Disconnect the cable from the negative (-) battery terminal.
      WARNING:

      Wait at least 90 seconds after disconnecting the cable from the negative (-) battery terminal to disable the SRS system.

    7. Using a service wire, connect terminals 2 (BDL+) and 1 (BDL-) of connector E.
      NOTE:

      Do not forcibly insert the service wire into the terminals of the connector when connecting the wire.

    8. Measure the resistance according to the value(s) in the table below.

      Standard Resistance

      Tester Connection Condition Specified Condition
      N36-1 (BDL+) - N36-2 (BDL-) Always Below 1 Ω
    9. Disconnect the service wire from connector E.
    10. Measure the resistance according to the value(s) in the table below.

      Standard Resistance

      Tester Connection Condition Specified Condition
      N36-1 (BDL+) - N36-2 (BDL-) Always 1 MΩ or higher
      N36-1 (BDL+) - Body ground Always 1 MΩ or higher
      N36-2 (BDL-) - Body ground Always 1 MΩ or higher

      Result

      Proceed to
      OK
      NG

    Result: 

    NG 

    See step  7

    Result: 

    OK 

    See step  5

  5. CHECK SIDE NO. 2 AIRBAG SENSOR ASSEMBLY LH 
    1. Connect the connectors to the door side airbag sensor LH and airbag ECU assembly.
      GTY447346Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
      *1 Side No. 2 Airbag Sensor Assembly RH
      *2 Airbag ECU Assembly
    2. Interchange the side No. 2 airbag sensor assembly LH with RH and connect the connectors.
    3. Connect the cable to the negative (-) battery terminal.
    4. Turn the engine switch on (IG), and wait for at least 60 seconds.
    5. Clear the DTCs stored in memory.

      Body Electrical > SRS Airbag > Clear DTCs 

    6. Turn the engine switch off.
    7. Turn the engine switch on (IG), and wait for at least 60 seconds.
    8. Check for DTCs.

      Body Electrical > SRS Airbag > Trouble Codes 

      HINT: 

      Codes other than DTCs B1642, B1643, B1647 and B1648 may be output at this time, but they are not related to this check.

      Result

      Result Proceed to
      DTC B1647 or B1648 is output. A
      DTC B1642 or B1643 is output. B
      DTCs B1642, B1643, B1647 and B1648 are not output. C
    9. Turn the engine switch off.
    10. Disconnect the cable from the negative (-) battery terminal.
      WARNING:

      Wait at least 90 seconds after disconnecting the cable from the negative (-) battery terminal to disable the SRS system.

    11. Return the side No. 2 airbag sensor assembly LH and RH to their original positions and connect the connectors.

    Result: 

    B 

    REPLACE SIDE NO. 2 AIRBAG SENSOR ASSEMBLY LH. Refer to  REMOVAL [06/2018 - 08/2020]  , or refer to  REMOVAL [08/2020 - 08/2021]  , or refer to  REMOVAL [08/2021 - 09/2022] 

    Result: 

    C 

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

    Result: 

    A 

    See step  6

  6. CHECK DOOR SIDE AIRBAG SENSOR LH 
    1. Interchange the door side airbag sensor LH with RH and connect the connectors.
      GTY430525Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
      *1 Door Side Airbag Sensor RH
      *2 Side No. 2 Airbag Sensor Assembly LH
    2. Connect the cable to the negative (-) battery terminal.
    3. Turn the engine switch on (IG), and wait for at least 60 seconds.
    4. Clear the DTCs stored in memory.

      Body Electrical > SRS Airbag > Clear DTCs 

    5. Turn the engine switch off.
    6. Turn the engine switch on (IG), and wait for at least 60 seconds.
    7. Check for DTCs.

      Body Electrical > SRS Airbag > Trouble Codes 

      HINT: 

      Codes other than DTCs B1642, B1643, B1647 and B1648 may be output at this time, but they are not related to this check.

      Result

      Result Proceed to
      DTC B1647 or B1648 is output. A
      DTC B1642 or B1643 is output. B
      DTCs B1642, B1643, B1647 and B1648 are not output. C
    8. Turn the engine switch off.
    9. Disconnect the cable from the negative (-) battery terminal.
      WARNING:

      Wait at least 90 seconds after disconnecting the cable from the negative (-) battery terminal to disable the SRS system.

    10. Return the door side airbag sensor LH and RH to their original positions and connect the connectors.

    Result: 

    A 

    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] 

    Result: 

    B 

    REPLACE DOOR SIDE AIRBAG SENSOR LH. Refer to  REMOVAL [06/2018 - 08/2020]  , or refer to  REMOVAL [08/2020 - 08/2021]  , or refer to  REMOVAL [08/2021 - 09/2022] 

    Result: 

    C 

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

  7. CHECK FLOOR WIRE 
    1. Disconnect the floor wire connector from the front door wire LH.
      GTY779539Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
      *1 Door Side Airbag Sensor LH *2 Side No. 2 Airbag Sensor Assembly LH
      *3 Front Door Wire LH *4 Floor Wire
      *5 Service Wire - -
      *a Front view of wire harness connector
      (to Side No. 2 Airbag Sensor Assembly LH)      		 *b Front view of wire harness connector
      (to Front Door Wire LH)
    2. Connect the cable to the negative (-) battery terminal.
    3. Turn the engine switch on (IG).
    4. Measure the voltage according to the value(s) in the table below.

      Standard Voltage

      Tester Connection Condition Specified Condition
      JN2-10 (BDL+) - Body ground Engine switch on (IG) Below 1 V
      JN2-20 (BDL-) - Body ground Engine switch on (IG) Below 1 V
    5. Turn the engine switch off.
    6. Disconnect the cable from the negative (-) battery terminal.
      WARNING:

      Wait at least 90 seconds after disconnecting the cable from the negative (-) battery terminal to disable the SRS system.

    7. Using a service wire, connect terminals 1 (BDL+) and 2 (BDL-) of connector B.
      NOTE:

      Do not forcibly insert the service wire into the terminals of the connector when connecting the wire.

    8. Measure the resistance according to the value(s) in the table below.

      Standard Resistance

      Tester Connection Condition Specified Condition
      JN2-10 (BDL+) - JN2-20 (BDL-) Always Below 1 Ω
    9. Disconnect the service wire from connector B.
    10. Measure the resistance according to the value(s) in the table below.

      Standard Resistance

      Tester Connection Condition Specified Condition
      JN2-10 (BDL+) - JN2-20 (BDL-) Always 1 MΩ or higher
      JN2-10 (BDL+) - Body ground Always 1 MΩ or higher
      JN2-20 (BDL-) - Body ground Always 1 MΩ or higher

      Result

      Proceed to
      OK
      NG

    Result: 

    OK 

    REPLACE FRONT DOOR WIRE LH 

    Result: 

    NG 

    REPLACE FLOOR WIRE 

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