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HOMESERVICE MANUALSTOYOTA20254RUNNER SR5, 4WDREPAIR AND DIAGNOSIS (SINGLE PAGE)RESTRAINTSAIR BAG, SRSOCCUPANT CLASSIFICATION SYSTEM - DIAGNOSTIC CODES, SYMPTOM TESTS & CIRCUIT TESTSOCCUPANT CLASSIFICATION SYSTEMLIN COMMUNICATION CIRCUIT [12/2024 - ]PROCEDURE
2025 Toyota 4Runner SR5, 4WD

LIN Communication Circuit [12/2024 - ]: Procedure

2025 Toyota 4Runner SR5, 4WDSECTION Procedure
  1. CHECK ERROR CODE 
    1. Check the Error Code.

      Result

      Result Proceed to
      Error code 17 is output A
      Error code 18 is output B
      Error code 17 and 18 are output C

    Result: 

    B 

    See step  7

    Result: 

    C 

    See step  12

    Result: 

    A 

    See step  2

  2. 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 60 seconds.
    3. Check that the connectors are properly connected to the airbag ECU assembly and front seat adjuster assembly RH (front occupant classification sensor LH).

      OK

      The connectors are properly connected.

      Result

      Proceed to
      OK
      NG

    Result: 

    NG 

    CONNECT CONNECTORS PROPERLY 

    Result: 

    OK 

    See step  3

  3. CHECK CONNECTORS 
    1. Disconnect the airbag ECU assembly connector.
      GTY984871Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
      *1 Front Seat Adjuster Assembly RH (Front Occupant Classification Sensor LH)
      *2 Airbag ECU Assembly
      *3 Wire Harness
    2. Disconnect the front seat adjuster assembly RH (front occupant classification sensor LH) connector.
    3. 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 

    REPAIR OR REPLACE HARNESS OR CONNECTOR 

    Result: 

    OK 

    See step  4

  4. CHECK HARNESS AND CONNECTOR (AIRBAG ECU ASSEMBLY - FRONT SEAT ADJUSTER ASSEMBLY RH) 
    1. Measure the resistance according to the value(s) in the table below.

      Standard Resistance

      Tester Connection Condition Specified Condition
      S3-24 (SVC) - e10-1 (SVC1) Always Below 1 Ω
      S3-32 (SIG) - e10-2 (SIG1) Always Below 1 Ω
      S3-31 (SGD) - e10-3 (SGD1) Always Below 1 Ω
      GTY1273796Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
      *1 Front Seat Adjuster Assembly RH
      *2 Airbag ECU Assembly
      *3 Wire Harness
      *a Front view of wire harness connector
      (to Airbag ECU Assembly)
      *b Front view of wire harness connector
      (to Front Seat Adjuster Assembly RH (Front Occupant Classification Sensor LH))

      Result

      Proceed to
      OK
      NG

    Result: 

    NG 

    REPAIR OR REPLACE HARNESS OR CONNECTOR 

    Result: 

    OK 

    See step  5

  5. REPLACE FRONT SEAT ADJUSTER ASSEMBLY RH 
    1. Connect the airbag ECU assembly connector.
    2. Replace the front seat adjuster assembly RH with a new one.

      for Manual Seat: Refer to REMOVAL [12/2024 - ]

      for Power Seat: Refer to REMOVAL [12/2024 - ]

      Result

      Proceed to
      NEXT

    Result: 

    NEXT 

    See step  6

  6. PERFORM ZERO POINT CALIBRATION 
    1. Using the GTS, perform "Occupant Detection Sensor Zero Point Calibration".

      Refer to INITIALIZATION [12/2024 - ]

      Result

      Proceed to
      NEXT

    Result: 

    NEXT 

    END 

  7. 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 60 seconds.
    3. Check that the connectors are properly connected to the airbag ECU assembly and front seat adjuster assembly RH (rear occupant classification sensor LH).

      OK

      The connectors are properly connected.

      Result

      Proceed to
      OK
      NG

    Result: 

    NG 

    CONNECT CONNECTORS PROPERLY 

    Result: 

    OK 

    See step  8

  8. CHECK CONNECTORS 
    1. Disconnect the airbag ECU assembly connector.
      GTY984871Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
      *1 Front Seat Adjuster Assembly RH (Rear Occupant Classification Sensor LH)
      *2 Airbag ECU Assembly
      *3 Wire Harness
    2. Disconnect the front seat adjuster assembly RH (rear occupant classification sensor LH) connector.
    3. 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 

    REPAIR OR REPLACE HARNESS OR CONNECTOR 

    Result: 

    OK 

    See step  9

  9. CHECK HARNESS AND CONNECTOR (AIRBAG ECU ASSEMBLY - FRONT SEAT ADJUSTER ASSEMBLY RH) 
    1. Measure the resistance according to the value(s) in the table below.

      Standard Resistance

      Tester Connection Condition Specified Condition
      S3-24 (SVC) - e11-1 (SVC3) Always Below 1 Ω
      S3-32 (SIG) - e11-2 (SIG3) Always Below 1 Ω
      S3-31 (SGD) - e11-3 (SGD3) Always Below 1 Ω
      GTY1273795Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
      *1 Front Seat Adjuster Assembly RH
      *2 Airbag ECU Assembly
      *3 Wire Harness
      *a Front view of wire harness connector
      (to Airbag ECU Assembly)
      *b Front view of wire harness connector
      (to Front Seat Adjuster Assembly RH (Rear Occupant Classification Sensor LH))

      Result

      Proceed to
      OK
      NG

    Result: 

    NG 

    REPAIR OR REPLACE HARNESS OR CONNECTOR 

    Result: 

    OK 

    See step  10

  10. REPLACE FRONT SEAT ADJUSTER ASSEMBLY RH 
    1. Connect the airbag ECU assembly connector.
    2. Replace the front seat adjuster assembly RH with a new one.

      for Manual Seat: Refer to REMOVAL [12/2024 - ]

      for Power Seat: Refer to REMOVAL [12/2024 - ]

      Result

      Proceed to
      NEXT

    Result: 

    NEXT 

    See step  11

  11. PERFORM ZERO POINT CALIBRATION 
    1. Using the GTS, perform "Occupant Detection Sensor Zero Point Calibration".

      Refer to INITIALIZATION [12/2024 - ]

      Result

      Proceed to
      NEXT

    Result: 

    NEXT 

    END 

  12. 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 60 seconds.
    3. Check that the connectors are properly connected to the airbag ECU assembly and front seat adjuster assembly RH.

      OK

      The connectors are properly connected.

      Result

      Proceed to
      OK
      NG

    Result: 

    NG 

    CONNECT CONNECTORS PROPERLY 

    Result: 

    OK 

    See step  13

  13. CHECK CONNECTORS 
    1. Disconnect the airbag ECU assembly connector.
      GTY985316Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
      *1 Front Seat Adjuster Assembly RH
      *2 Airbag ECU Assembly
      *3 Wire Harness
    2. Disconnect the front seat adjuster assembly RH connector.
    3. 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 

    REPAIR OR REPLACE HARNESS OR CONNECTOR 

    Result: 

    OK 

    See step  14

  14. CHECK HARNESS AND CONNECTOR (AIRBAG ECU ASSEMBLY - FRONT SEAT ADJUSTER ASSEMBLY RH) 
    1. Measure the resistance according to the value(s) in the table below.

      Standard Resistance

      Tester Connection Condition Specified Condition
      S3-24 (SVC) - e10-1 (SVC1) Always Below 1 Ω
      S3-24 (SVC) - e11-1 (SVC3) Always Below 1 Ω
      S3-32 (SIG) - e10-2 (SIG1) Always Below 1 Ω
      S3-32 (SIG) - e11-2 (SIG3) Always Below 1 Ω
      S3-31 (SGD) - e10-3 (SGD1) Always Below 1 Ω
      S3-31 (SGD) - e11-3 (SGD3) Always Below 1 Ω
      GTY1276019Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
      *1 Front Seat Adjuster Assembly RH
      *2 Airbag ECU Assembly
      *3 Wire Harness
      *a Front view of wire harness connector
      (to Airbag ECU Assembly)
      *b Front view of wire harness connector
      (to Front Seat Adjuster Assembly RH (Front Occupant Classification Sensor LH))
      *c Front view of wire harness connector
      (to Front Seat Adjuster Assembly RH (Rear Occupant Classification Sensor LH))

      Result

      Proceed to
      OK
      NG

    Result: 

    NG 

    REPAIR OR REPLACE HARNESS OR CONNECTOR 

    Result: 

    OK 

    See step  15

  15. CHECK HARNESS AND CONNECTOR (AIRBAG ECU ASSEMBLY - FRONT SEAT ADJUSTER ASSEMBLY RH) 
    1. Measure the resistance according to the value(s) in the table below.

      Standard Resistance

      Tester Connection Condition Specified Condition
      S3-32 (SIG) - Other terminals and body ground Always 10 kΩ or higher
      e10-2 (SIG1) - Other terminals and body ground Always 10 kΩ or higher
      e11-2 (SIG3) - Other terminals and body ground Always 10 kΩ or higher
      GTY1272889Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
      *1 Front Seat Adjuster Assembly RH
      *2 Airbag ECU Assembly
      *3 Wire Harness
      *a Front view of wire harness connector
      (to Airbag ECU Assembly)
      *b Front view of wire harness connector
      (to Front Seat Adjuster Assembly RH (Front Occupant Classification Sensor LH))
      *c Front view of wire harness connector
      (to Front Seat Adjuster Assembly RH (Rear Occupant Classification Sensor LH))

      Result

      Proceed to
      OK
      NG

    Result: 

    NG 

    REPAIR OR REPLACE HARNESS OR CONNECTOR 

    Result: 

    OK 

    See step  16

  16. CHECK HARNESS AND CONNECTOR (AIRBAG ECU ASSEMBLY - FRONT SEAT ADJUSTER ASSEMBLY RH) 
    1. Connect the cable to the negative (-) auxiliary battery terminal, and wait for at least 2 seconds.
      GTY1272889Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
      *1 Front Seat Adjuster Assembly RH
      *2 Airbag ECU Assembly
      *3 Wire Harness
      *a Front view of wire harness connector
      (to Airbag ECU Assembly)
      *b Front view of wire harness connector
      (to Front Seat Adjuster Assembly RH (Front Occupant Classification Sensor LH))
      *c Front view of wire harness connector
      (to Front Seat Adjuster Assembly RH (Rear Occupant Classification Sensor LH))
    2. Turn the ignition switch to ON.
    3. Measure the voltage according to the value(s) in the table below.

      Standard Voltage

      Tester Connection Condition Specified Condition
      S3-32 (SIG) - Body ground Ignition switch ON Below 1 V
      e10-2 (SIG1) - Body ground Ignition switch ON Below 1 V
      e11-2 (SIG3) - Body ground Ignition switch ON Below 1 V

      Result

      Proceed to
      OK
      NG

    Result: 

    NG 

    REPAIR OR REPLACE HARNESS OR CONNECTOR 

    Result: 

    OK 

    See step  17

  17. REPLACE AIRBAG ECU ASSEMBLY 
    1. Connect the front seat adjuster assembly RH connector.
    2. Replace the airbag ECU assembly with a new one.

      Refer to REMOVAL [12/2024 - ]

      Result

      Proceed to
      NEXT

    Result: 

    NEXT 

    See step  18

  18. PERFORM ZERO POINT CALIBRATION 
    1. Using the GTS, perform "Occupant Detection Sensor Zero Point Calibration".

      Refer to INITIALIZATION [12/2024 - ]

      Result

      Proceed to
      NEXT

    Result: 

    NEXT 

    END 

RENDER: 1.0x

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Stop DIY work and contact a certified mechanic immediately if any of the following apply:

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