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Home >> Toyota >> 2020 >> RAV4 XLE, AWD >> Repair and Diagnosis >> External Pages >> Different car >> Section 2 (Airbag System - Diagnostic Codes (1 Of 2)) >> Airbag System >> DTC B1617: Front Airbag Sensor Lost Communication (LH); DTC B1618: Front Airbag Sensor LH Initialization [08/2020 - ] >> Procedure

DTC B1617: Front Airbag Sensor Lost Communication (LH); DTC B1618: Front Airbag Sensor LH Initialization [08/2020 - ]: Procedure

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  1. CHECK CONNECTION OF CONNECTORS 
    1. Turn the ignition switch off.
    2. Disconnect the cable from the negative (-) auxiliary battery terminal, and wait for at least 90 seconds.
    3. Check that the connectors are properly connected to the airbag ECU assembly and front airbag sensor LH.

      Result

      Proceed to
      The connectors are properly connected
      The connectors are not properly connected

    Result: 

    The connectors are not properly connected 

    CONNECT CONNECTORS PROPERLY 

    Result: 

    The connectors are properly connected 

    See step  2

  2. CHECK CONNECTORS 
    1. Disconnect the connectors from the airbag ECU assembly and front airbag sensor LH.
    2. Check that the connectors (on the airbag ECU assembly side and front airbag sensor LH side) are not damaged.
      GTY863517Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
      *1 Front Airbag Sensor LH
      *2 Airbag ECU Assembly
      *3 Engine Room Main Wire
      *4 Instrument Panel Wire

      Result

      Proceed to
      The connectors are not deformed or damaged
      The connectors are deformed or damaged

    Result: 

    The connectors are deformed or damaged 

    REPLACE INSTRUMENT PANEL WIRE OR ENGINE ROOM MAIN WIRE 

    Result: 

    The connectors are not deformed or damaged 

    See step  3

  3. CHECK FRONT AIRBAG SENSOR LH CIRCUIT 
    1. Connect the cable to the negative (-) auxiliary battery terminal, and wait for at least 2 seconds.
      GTY933820Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
      *1 Front Airbag Sensor LH
      *2 Airbag ECU Assembly
      *3 Engine Room Main Wire
      *4 Instrument Panel Wire
      *5 Service Wire
      *a Front view of wire harness connector
      (to Front Airbag Sensor LH)
      *b Front view of wire harness connector
      (to Airbag ECU Assembly)
    2. Turn the ignition switch to ON.
    3. Measure the voltage according to the value(s) in the table below.

      Standard Voltage

      Tester Connection Switch Condition Specified Condition
      A47-2 (+SL) - Body ground Ignition switch ON Below 1 V
      A47-1 (-SL) - Body ground Ignition switch ON Below 1 V
    4. Turn the ignition switch off.
    5. Disconnect the cable from the negative (-) auxiliary battery terminal, and wait for at least 90 seconds.
    6. Using a service wire, connect terminals 30 (+SL) and 31 (-SL) of connector B.
      NOTE:

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

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

      Standard Resistance

      Tester Connection Condition Specified Condition
      A47-2 (+SL) - A47-1 (-SL) 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
      A47-2 (+SL) - A47-1 (-SL) Always 1 MΩ or higher
      A47-2 (+SL) - Body ground Always 1 MΩ or higher
      A47-1 (-SL) - Body ground Always 1 MΩ or higher

      Result

      Proceed to
      OK
      NG

    Result: 

    NG 

    See step  5

    Result: 

    OK 

    See step  4

  4. CHECK FRONT AIRBAG SENSOR LH 
    1. Connect the connectors to the airbag ECU assembly.
      GTY931034Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
      *1 Front Airbag Sensor RH
      *2 Airbag ECU Assembly
    2. Interchange the front airbag sensor LH with RH and connect the connectors to them.
    3. Connect the cable to the negative (-) auxiliary battery terminal, and wait for at least 2 seconds.
    4. Turn the ignition switch to ON, and wait for at least 60 seconds.
    5. Clear the DTCs stored in memory.

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

      Body Electrical > SRS Airbag > Clear DTCs 

    6. Turn the ignition switch off.
    7. Turn the ignition switch to ON, and wait for at least 60 seconds.
    8. Check for DTCs.

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

      Body Electrical > SRS Airbag > Trouble Codes 

      Result

      Proceed to
      DTC B1617 or B1618 is output
      DTC B1612 or B1613 is output
      DTCs B1612, B1613, B1617 and B1618 are not output

      HINT: 

      Codes other than DTC B1612, B1613, B1617 and B1618 may be output at this time, but they are not related to this check.

    9. Turn the ignition switch off.
    10. Disconnect the cable from the negative (-) auxiliary battery terminal, and wait for at least 90 seconds.
    11. Return the front airbag sensor RH and LH to their original positions and connect the connectors to them.

    Result: 

    DTC B1617 or B1618 is output 

    REPLACE AIRBAG ECU ASSEMBLY. Refer to  REMOVAL [08/2020 - 12/2021]  , or refer to  REMOVAL [12/2021 - 10/2022]  , or refer to  REMOVAL [10/2022 - 10/2023]  , or refer to  REMOVAL [10/2023 - ] 

    Result: 

    DTC B1612 or B1613 is output 

    REPLACE FRONT AIRBAG SENSOR LH. Refer to  REMOVAL [08/2020 - 12/2021]  , or refer to  REMOVAL [12/2021 - 10/2022]  , or refer to  REMOVAL [10/2022 - 10/2023]  , or refer to  REMOVAL [10/2023 - ] 

    Result: 

    DTCs B1612, B1613, B1617 and B1618 are not output 

    USE SIMULATION METHOD TO CHECK. Refer to  HOW TO PROCEED WITH TROUBLESHOOTING [11/2018 - ] 

  5. CHECK CONNECTORS 
    1. Disconnect the instrument panel wire connector from the engine room main wire.
      GTY944513Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
      *1 Front Airbag Sensor LH
      *2 Airbag ECU Assembly
      *3 Engine Room Main Wire
      *4 Instrument Panel Wire
    2. Check that the connectors (on the engine room main wire side and instrument panel wire side) are not damaged.

      Result

      Proceed to
      The connectors are not deformed or damaged
      The connectors are deformed or damaged

    Result: 

    The connectors are deformed or damaged 

    REPLACE INSTRUMENT PANEL WIRE OR ENGINE ROOM MAIN WIRE 

    Result: 

    The connectors are not deformed or damaged 

    See step  6

  6. CHECK INSTRUMENT PANEL WIRE 
    1. Connect the cable to the negative (-) auxiliary battery terminal, and wait for at least 2 seconds.
      GTY879702Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
      *1 Front Airbag Sensor LH
      *2 Airbag ECU Assembly
      *3 Engine Room Main Wire
      *4 Instrument Panel Wire
      *5 Service Wire
      *a Front view of wire harness connector
      (to Engine Room Main Wire)
      *b Front view of wire harness connector
      (to Airbag ECU Assembly)
    2. Turn the ignition switch to ON.
    3. Measure the voltage according to the value(s) in the table below.

      Standard Voltage

      Tester Connection Switch Condition Specified Condition
      GA1-2 (+SL) - Body ground Ignition switch ON Below 1 V
      GA1-4 (-SL) - Body ground Ignition switch ON Below 1 V
    4. Turn the ignition switch off.
    5. Disconnect the cable from the negative (-) auxiliary battery terminal, and wait for at least 90 seconds.
    6. Using a service wire, connect terminals 30 (+SL) and 31 (-SL) of connector B.
      NOTE:

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

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

      Standard Resistance

      Tester Connection Condition Specified Condition
      GA1-2 (+SL) - GA1-4 (-SL) 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
      GA1-2 (+SL) - GA1-4 (-SL) Always 1 MΩ or higher
      GA1-2 (+SL) - Body ground Always 1 MΩ or higher
      GA1-4 (-SL) - Body ground Always 1 MΩ or higher

      Result

      Proceed to
      OK
      NG

    Result: 

    OK 

    REPLACE ENGINE ROOM MAIN WIRE 

    Result: 

    NG 

    REPLACE INSTRUMENT PANEL WIRE 

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