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Home >> Toyota >> 2021 >> Highlander LE, 4WD >> Repair and Diagnosis >> Restraints >> Air Bag, SRS >> Airbag System - Diagnostic Codes (2 Of 7) >> Airbag System >> DTC B0020-1A: Left Side Airbag Deployment Control Circuit Resistance Below Threshold [11/2023 - ] >> Procedure

DTC B0020-1A: Left Side Airbag Deployment Control Circuit Resistance Below Threshold [11/2023 - ]: Procedure

  1. CLEAR DTC 

    Pre-procedure1

    1. Turn the ignition switch to ON, and wait for at least 60 seconds.

      Procedure1

    2. Clear the DTCs stored in memory.

      Body Electrical > SRS Airbag > Clear DTCs 

      Result

      Proceed to
      NEXT

      Post-procedure1

    3. Turn the ignition switch off.

    Result: 

    NEXT 

    See step  2

  2. CHECK DTC 

    Pre-procedure1

    1. Turn the ignition switch to ON, and wait for at least 60 seconds.

      Procedure1

    2. Check for DTCs.

      Body Electrical > SRS Airbag > Trouble Codes 

      Result

      Result Proceed to
      B0020-1A is output A
      B0020-1A is not output B

      Post-procedure1

    3. None

    Result: 

    B 

    USE SIMULATION METHOD TO CHECK 

    Refer to HOW TO PROCEED WITH TROUBLESHOOTING [12/2019 - ]

    Result: 

    A 

    See step  3

  3. CHECK CONNECTION OF CONNECTORS 

    Pre-procedure1

    1. Turn the ignition switch off.
    2. Disconnect the cable from the negative (-) auxiliary battery terminal, and wait for at least 60 seconds.

      Procedure1

    3. Check that the connectors are properly connected to the front seat airbag assembly LH and airbag sensor assembly.

      OK

      The connectors are properly connected.

      Result

      Proceed to
      OK
      NG

      Post-procedure1

    4. None

    Result: 

    NG 

    CONNECT CONNECTORS PROPERLY 

    Result: 

    OK 

    See step  4

  4. CHECK CONNECTORS 

    Pre-procedure1

    1. Disconnect the airbag sensor assembly connector.
      GTY972912Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
      *1 Front Seat Airbag Assembly LH
      *2 Airbag Sensor Assembly
      *3 Wire Harness
    2. Disconnect the front seat airbag assembly LH connector.

      Procedure1

    3. Check that the terminals of the connectors are not deformed or damaged.

      OK

      The terminals are not deformed or damaged.

    4. Check that the short springs of the activation prevention mechanism of the wire harness connector are not deformed or damaged.

      OK

      The short springs are not deformed or damaged.

      Result

      Proceed to
      OK
      NG

      Post-procedure1

    5. None

    Result: 

    NG 

    REPAIR OR REPLACE HARNESS OR CONNECTOR 

    Result: 

    OK 

    See step  5

  5. CLEAR DTC 

    Pre-procedure1

    1. Connect the airbag sensor assembly connector.
      GTY1178706Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
      *1 Front Seat Airbag Assembly LH
      *2 Airbag Sensor Assembly
      *3 Wire Harness
      *4 SST
      *a Front view of wire harness connector
      (to Front Seat Airbag Assembly LH)
    2. Connect SST (resistance: 2.1 Ω) to connector C.
      WARNING:

      Never connect the tester to the front seat airbag assembly LH for measurement, as this may lead to a serious injury due to airbag deployment.

      NOTE:
      • Do not forcibly insert SST into the terminals of the connector when connecting SST.
      • Insert SST straight into the terminals of the connector.
      • SST: 09843-18061 
    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.

      Procedure1

    5. Clear the DTCs stored in memory.

      Body Electrical > SRS Airbag > Clear DTCs 

      Result

      Proceed to
      NEXT

      Post-procedure1

    6. Turn the ignition switch off.

    Result: 

    NEXT 

    See step  6

  6. CHECK FRONT SEAT AIRBAG ASSEMBLY LH 

    Pre-procedure1

    1. Turn the ignition switch to ON, and wait for at least 60 seconds.

      Procedure1

    2. Check for DTCs.

      Body Electrical > SRS Airbag > Trouble Codes 

      Result

      Result Proceed to
      B0020-1A is not output A
      B0020-1A is output B

      HINT: 

      Codes other than DTC B0020-1A may be output at this time, but they are not related to this check.

      Post-procedure1

    3. Turn the ignition switch off.
    4. Disconnect the cable from the negative (-) auxiliary battery terminal, and wait for at least 60 seconds.
    5. Disconnect SST from connector C.

    Result: 

    A 

    REPLACE FRONT SEAT AIRBAG ASSEMBLY LH 

    Refer to REMOVAL [11/2023 - ]

    Result: 

    B 

    See step  7

  7. CHECK HARNESS AND CONNECTOR 

    Pre-procedure1

    1. Disconnect the airbag sensor assembly connector.
      GTY1177991Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
      *1 Front Seat Airbag Assembly LH
      *2 Airbag Sensor Assembly
      *3 Wire Harness
      *a Front view of wire harness connector
      (to Front Seat Airbag Assembly LH)
      Release the activation prevention mechanism
    2. Release the activation prevention mechanism built into connector B.

      HINT: 

      Refer to SYSTEM DESCRIPTION [11/2023 - ]

      Procedure1

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

      Standard Resistance

      Tester Connection Condition Specified Condition
      Mt2-1 (SFL+) - Mt2-2 (SFL-) Always 1 MΩ or higher

      Result

      Proceed to
      OK
      NG

      Post-procedure1

    4. Restore the released activation prevention mechanism of connector B to its original condition.

    Result: 

    NG 

    REPAIR OR REPLACE HARNESS OR CONNECTOR 

    Result: 

    OK 

    See step  8

  8. CLEAR DTC 

    Pre-procedure1

    1. Connect the airbag sensor assembly connector.
      GTY972925Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
      *1 Front Seat Airbag Assembly LH
      *2 Airbag Sensor Assembly
      *3 Wire Harness
    2. Connect the front seat airbag assembly LH connector.
    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.

      Procedure1

    5. Clear the DTCs stored in memory.

      Body Electrical > SRS Airbag > Clear DTCs 

      Result

      Proceed to
      NEXT

      Post-procedure1

    6. Turn the ignition switch off.

    Result: 

    NEXT 

    See step  9

  9. CHECK DTC 

    Pre-procedure1

    1. Turn the ignition switch to ON, and wait for at least 60 seconds.

      Procedure1

    2. Check for DTCs.

      Body Electrical > SRS Airbag > Trouble Codes 

      Result

      Result Proceed to
      B0020-1A is not output A
      B0020-1A is output B

      HINT: 

      Codes other than DTC B0020-1A may be output at this time, but they are not related to this check.

      Post-procedure1

    3. None

    Result: 

    A 

    USE SIMULATION METHOD TO CHECK 

    Refer to HOW TO PROCEED WITH TROUBLESHOOTING [12/2019 - ]

    Result: 

    B 

    REPLACE AIRBAG SENSOR ASSEMBLY 

    Refer to REMOVAL [11/2023 - ]

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