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Home >> Lexus >> 2012 >> CT 200h F Sport >> Repair and Diagnosis >> Restraints >> Air Bag, SRS >> Airbag System (Diagnostic Codes (B1650/32 - B1905/74) & Symptom Tests) >> Airbag System >> DTC B1653/35: Seat Position Airbag Sensor Circuit Malfunction >> Procedure

DTC B1653/35: Seat Position Airbag Sensor Circuit Malfunction: Procedure

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

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

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

      OK

      The connectors are properly connected.

      HINT: 

      If the connectors are not connected securely, reconnect the connectors and proceed to the next inspection.

    4. Disconnect the connectors from the airbag sensor assembly, front seat inner belt assembly LH and seat position airbag sensor.
    5. Check that the terminals of the connectors are not damaged.

      OK

      The terminals are not deformed or damaged.

    NG → REPLACE WIRE HARNESS 

    OK: Go to next step 

  2. CHECK SEAT POSITION AIRBAG SENSOR CIRCUIT (OPEN) 
    1. Connect the connectors to the front seat inner belt assembly LH and floor wire.
      Fig 1: Identifying P1 Connector Terminals
      GTY348328Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
    2. Using SST, connect terminals 14 (LSP+) and 13 (LSP-) of connector B.
      NOTE:

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

      • SST: 09843-18040 
    3. Measure the resistance according to the value(s) in the table below.

      Standard Resistance

      Tester Connection Condition Specified Condition
      2 (LSP+) - 1 (LSP-) Always Below 1 Ω
      TEXT IN ILLUSTRATION

      *1 Seat Position Airbag Sensor *2 Airbag Sensor Assembly
      *3 Connector B *4 Connector E
      *a Front view of wire harness connector
      (to Airbag Sensor Assembly)      		 *b Front view of wire harness connector
      (to Seat Position Airbag Sensor)

    NG → See step   9 

    OK: Go to next step 

  3. CHECK SEAT POSITION AIRBAG SENSOR CIRCUIT (SHORT) 
    1. Disconnect SST from connector B.
      Fig 2: Identifying Seat Position Airbag Sensor Connector Terminals
      GTY353495Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
    2. Measure the resistance according to the value(s) in the table below.

      Standard Resistance

      Tester Connection Condition Specified Condition
      2 (LSP+) - 1 (LSP-) Always 1 MΩ or higher
      TEXT IN ILLUSTRATION

      *1 Seat Position Airbag Sensor
      *2 Airbag Sensor Assembly
      *3 Connector E
      *a Front view of wire harness connector
      (to Seat Position Airbag Sensor)

    NG → See step   10 

    OK: Go to next step 

  4. CHECK SEAT POSITION AIRBAG SENSOR CIRCUIT (SHORT TO B+) 
    1. Connect the cable to the negative (-) auxiliary battery terminal.
      Fig 3: Identifying Seat Position Airbag Sensor Connector Terminals
      GTY353495Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
    2. Turn the power switch on (IG).
    3. Measure the voltage according to the value(s) in the table below.

      Standard Voltage

      Tester Connection Switch Condition Specified Condition
      2 (LSP+) - Body ground Power switch on (IG) Below 1 V
      1 (LSP-) - Body ground Power switch on (IG) Below 1 V
      TEXT IN ILLUSTRATION

      *1 Seat Position Airbag Sensor
      *2 Airbag Sensor Assembly
      *3 Connector E
      *a Front view of wire harness connector
      (to Seat Position Airbag Sensor)

    NG → See step   11 

    OK: Go to next step 

  5. CHECK SEAT POSITION AIRBAG SENSOR CIRCUIT (SHORT TO GROUND) 
    1. Turn the power switch off.
      Fig 4: Identifying Seat Position Airbag Sensor Connector Terminals
      GTY353495Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
    2. Disconnect the cable from the negative (-) auxiliary battery terminal.
      WARNING:

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

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

      Standard Resistance

      Tester Connection Condition Specified Condition
      2 (LSP+) - Body ground Always 1 MΩ or higher
      1 (LSP-) - Body ground Always 1 MΩ or higher
      TEXT IN ILLUSTRATION

      *1 Seat Position Airbag Sensor
      *2 Airbag Sensor Assembly
      *3 Connector E
      *a Front view of wire harness connector
      (to Seat Position Airbag Sensor)

    NG → See step   12 

    OK: Go to next step 

  6. CHECK SEAT POSITION AIRBAG SENSOR 
    1. Connect the connectors to the airbag sensor assembly and seat position airbag sensor.
      Fig 5: Identifying Seat Position Airbag Sensor
      GTY245533Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
    2. Connect the cable to the negative (-) auxiliary battery terminal.
    3. Turn the power switch on (IG), and wait for at least 60 seconds.
    4. Clear the DTCs stored in memory. Refer to DTC CHECK / CLEAR .
    5. Turn the power switch off.
    6. Turn the power switch on (IG), and wait for at least 60 seconds.
    7. Check for DTCs. Refer to DTC CHECK / CLEAR .

      OK

      DTC B1653/35 is not output.

      TEXT IN ILLUSTRATION

      *1 Seat Position Airbag Sensor
      *2 Airbag Sensor Assembly

      HINT: 

      Codes other than DTC B1653/35 may be output at this time, but they are not related to this check.

    NG → See step   7 

    OK → See step   13 

  7. REPLACE SEAT POSITION AIRBAG SENSOR 
    1. Turn the power switch off.
    2. Disconnect the cable from the negative (-) auxiliary battery terminal.
      WARNING:

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

    3. Replace the seat position airbag sensor with a known good one. Refer to REMOVAL .

      HINT: 

      Perform the following inspection using known good parts from another vehicle if possible.

    NEXT: Go to next step 

  8. CHECK AIRBAG SENSOR ASSEMBLY 
    1. Connect the cable to the negative (-) auxiliary battery terminal.
      Fig 6: Identifying Seat Position Airbag Sensor
      GTY245533Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
    2. Turn the power switch on (IG), and wait for at least 60 seconds.
    3. Clear the DTCs stored in memory. Refer to DTC CHECK / CLEAR .
    4. Turn the power switch off.
    5. Turn the power switch on (IG), and wait for at least 60 seconds.
    6. Check for DTCs. Refer to DTC CHECK / CLEAR .

      OK

      DTC B1653/35 is not output.

      TEXT IN ILLUSTRATION

      *1 Seat Position Airbag Sensor
      *2 Airbag Sensor Assembly

      HINT: 

      Codes other than DTC B1653/35 may be output at this time, but they are not related to this check.

    NG → See step   14 

    OK → END 

  9. CHECK FLOOR WIRE (OPEN) 
    1. Disconnect the floor wire from the front seat inner belt assembly LH.
      Fig 7: Identifying P1 And P3 Connector Terminals
      GTY354940Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

      HINT: 

      SST has already been inserted into connector B.

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

      Standard Resistance

      Tester Connection Condition Specified Condition
      P3-4 (LSP+) - P3-3 (LSP-) Always Below 1 Ω
      RESULT

      Result Proceed to
      NG A
      OK (for Manual seat) B
      OK (for Power seat) C
      TEXT IN ILLUSTRATION

      *1 Seat Position Airbag Sensor *2 Airbag Sensor Assembly
      *3 Front Seat Inner Belt Assembly LH *4 Floor Wire
      *5 Connector B *6 Connector C
      *a Front view of wire harness connector
      (to Airbag Sensor Assembly)      		 *b Front view of wire harness connector
      (to Front Seat Inner Belt Assembly LH)

    B → See step   15 

    C → See step   16 

    A → REPLACE FLOOR WIRE 

  10. CHECK FLOOR WIRE (SHORT) 
    1. Disconnect the floor wire from the front seat inner belt assembly LH.
      Fig 8: Identifying P3 Connector Terminals
      GTY351913Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
    2. Measure the resistance according to the value(s) in the table below.

      Standard Resistance

      Tester Connection Condition Specified Condition
      P3-4 (LSP+) - P3-3 (LSP-) Always 1 MΩ or higher
      RESULT

      Result Proceed to
      NG A
      OK (for Manual seat) B
      OK (for Power seat) C
      TEXT IN ILLUSTRATION

      *1 Seat Position Airbag Sensor
      *2 Airbag Sensor Assembly
      *3 Front Seat Inner Belt Assembly LH
      *4 Floor Wire
      *5 Connector C
      *a Front view of wire harness connector
      (to Front Seat Inner Belt Assembly LH)

    B → See step   15 

    C → See step   16 

    A → REPLACE FLOOR WIRE 

  11. CHECK FLOOR WIRE (SHORT TO B+) 
    1. Turn the power switch off.
      Fig 9: Identifying P3 Connector Terminals
      GTY351913Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
    2. Disconnect the cable from the negative (-) auxiliary battery terminal.
      WARNING:

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

    3. Disconnect the floor wire from the front seat inner belt assembly LH.
    4. Connect the cable to the negative (-) auxiliary battery terminal.
    5. Turn the power switch on (IG).
    6. Measure the voltage according to the value(s) in the table below.

      Standard Voltage

      Tester Connection Switch Condition Specified Condition
      P3-4 (LSP+) - Body ground Power switch on (IG) Below 1 V
      P3-3 (LSP-) - Body ground Power switch on (IG) Below 1 V
      RESULT

      Result Proceed to
      NG A
      OK (for Manual seat) B
      OK (for Power seat) C
      TEXT IN ILLUSTRATION

      *1 Seat Position Airbag Sensor
      *2 Airbag Sensor Assembly
      *3 Front Seat Inner Belt Assembly LH
      *4 Floor Wire
      *5 Connector C
      *a Front view of wire harness connector
      (to Front Seat Inner Belt Assembly LH)

    B → See step   15 

    C → See step   16 

    A → REPLACE FLOOR WIRE 

  12. CHECK FLOOR WIRE (SHORT TO GROUND) 
    1. Disconnect the floor wire from the front seat inner belt assembly LH.
      Fig 10: Identifying P3 Connector Terminals
      GTY351913Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
    2. Measure the resistance according to the value(s) in the table below.

      Standard Resistance

      Tester Connection Condition Specified Condition
      P3-4 (LSP+) - Body ground Always 1 MΩ or higher
      P3-3 (LSP-) - Body ground Always 1 MΩ or higher
      RESULT

      Result Proceed to
      NG A
      OK (for Manual seat) B
      OK (for Power seat) C
      TEXT IN ILLUSTRATION

      *1 Seat Position Airbag Sensor
      *2 Airbag Sensor Assembly
      *3 Front Seat Inner Belt Assembly LH
      *4 Floor Wire
      *5 Connector C
      *a Front view of wire harness connector
      (to Front Seat Inner Belt Assembly LH)

    B → See step   15 

    C → See step   16 

    A → REPLACE FLOOR WIRE 

  13. USE SIMULATION METHOD TO CHECK. Refer to  HOW TO PROCEED WITH TROUBLESHOOTING 
  14. REPLACE AIRBAG SENSOR ASSEMBLY. Refer to  REMOVAL 
  15. REPLACE FRONT SEAT INNER BELT ASSEMBLY LH. Refer to  REMOVAL 
  16. REPLACE FRONT SEAT INNER BELT ASSEMBLY LH. Refer to  REMOVAL 
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