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Home >> Toyota >> 2014 >> Avalon XLE >> Repair and Diagnosis >> Restraints >> Air Bag, SRS >> Supplemental Restraint System (Diagnostic Codes & Symptom Tests) (Except Hybrid) >> Airbag System >> DTC B1653/35: Seat Position Airbag Sensor Circuit Malfunction [10/2013 - ] >> Procedure

DTC B1653/35: Seat Position Airbag Sensor Circuit Malfunction [10/2013 - ]: Procedure

  1. CHECK 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, front seat inner belt assembly LH and seat position airbag sensor.

      OK

      The connectors are properly connected.

      HINT: 

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

    4. Disconnect the connectors from the airbag ECU 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.
      GTY379442Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
    2. Using a service wire, connect terminals 14 (LSP+) and 13 (LSP-) of connector B.
      NOTE:

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

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

      Standard Resistance

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

      *1 Seat Position Airbag Sensor
      *2 Airbag ECU Assembly
      *3 Service Wire
      *a Front view of wire harness connector
      (to Airbag ECU Assembly)
      *b Front view of wire harness connector
      (to Seat Position Airbag Sensor)

    NG → See step   8 

    OK: Go to next step 

  3. CHECK SEAT POSITION AIRBAG SENSOR CIRCUIT (SHORT) 
    1. Disconnect the service wire from connector B.
      GTY380775Courtesy 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
      1 (LSP+) - 2 (LSP-) Always 1 MΩ or higher
      TEXT IN ILLUSTRATION

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

    NG → See step   9 

    OK: Go to next step 

  4. CHECK SEAT POSITION AIRBAG SENSOR CIRCUIT (SHORT TO B+) 
    1. Connect the cable to the negative (-) battery terminal.
      GTY380775Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
    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
      1 (LSP+) - Body ground Engine switch on (IG) Below 1 V
      2 (LSP-) - 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.

      TEXT IN ILLUSTRATION

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

    NG → See step   10 

    OK: Go to next step 

  5. CHECK SEAT POSITION AIRBAG SENSOR CIRCUIT (SHORT TO GROUND) 
    1. Measure the resistance according to the value(s) in the table below.
      GTY380775Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

      Standard Resistance

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

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

    NG → See step   11 

    OK: Go to next step 

  6. CHECK DTC 
    1. Connect the connectors to the airbag ECU assembly and seat position airbag sensor.
      GTY328706Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
    2. Connect the cable to the negative (-) battery terminal.
    3. Clear the DTCs stored in memory. Refer to DTC CHECK / CLEAR [10/2013 - ] .
    4. Turn the engine switch off.
    5. Turn the engine switch on (IG), and wait for at least 60 seconds.
    6. Check for DTCs. Refer to DTC CHECK / CLEAR [10/2013 - ] .

      OK

      DTC B1653/35 is not output.

      HINT: 

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

      TEXT IN ILLUSTRATION

      *1 Seat Position Airbag Sensor
      *2 Airbag ECU Assembly

    NG → See step   7 

    OK → See step   12 

  7. CHECK SEAT POSITION AIRBAG SENSOR 
    1. Turn the engine switch off.
      GTY328706Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
    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. Replace the seat position airbag sensor with a known good one. Refer to REMOVAL [10/2013 - ] .

      HINT: 

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

    4. Connect the cable to the negative (-) battery terminal.
    5. Clear the DTCs stored in memory. Refer to DTC CHECK / CLEAR [10/2013 - ] .
    6. Turn the engine switch off.
    7. Turn the engine switch on (IG), and wait for at least 60 seconds.
    8. Check for DTCs. Refer to DTC CHECK / CLEAR [10/2013 - ] .

      OK

      DTC B1653/35 is not output.

      HINT: 

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

    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. Restore the seat position airbag sensor that was installed for testing to its original location. Refer to REMOVAL [10/2013 - ] .
      TEXT IN ILLUSTRATION

      *1 Seat Position Airbag Sensor
      *2 Airbag ECU Assembly

    NG → See step   13 

    OK → See step   15 

  8. CHECK FLOOR WIRE (OPEN) 
    1. Disconnect the floor wire from the front seat inner belt assembly LH.
      GTY381595Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

      HINT: 

      The service wire 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
      J2-3 (LSP+) - J2-4 (LSP-) Always Below 1 Ω
    3. Disconnect the service wire from the connector B.
      TEXT IN ILLUSTRATION

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

    NG → REPLACE FLOOR WIRE 

    OK → See step   14 

  9. CHECK FLOOR WIRE (SHORT) 
    1. Disconnect the floor wire from the front seat inner belt assembly LH.
      GTY369578Courtesy 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
      J2-3 (LSP+) - J2-4 (LSP-) Always 1 MΩ or higher
      TEXT IN ILLUSTRATION

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

    NG → REPLACE FLOOR WIRE 

    OK → See step   14 

  10. CHECK FLOOR WIRE (SHORT TO B+) 
    1. Disconnect the floor wire from the front seat inner belt assembly LH.
      GTY369578Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
    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
      J2-3 (LSP+) - Body ground Engine switch on (IG) Below 1 V
      J2-4 (LSP-) - Body ground Engine switch on (IG) Below 1 V
      TEXT IN ILLUSTRATION

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

    NG → REPLACE FLOOR WIRE 

    OK → See step   14 

  11. CHECK FLOOR WIRE (SHORT TO GROUND) 
    1. Disconnect the floor wire from the front seat inner belt assembly LH.
      GTY369578Courtesy 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
      J2-3 (LSP+) - Body ground Always 1 MΩ or higher
      J2-4 (LSP-) - Body ground Always 1 MΩ or higher
      TEXT IN ILLUSTRATION

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

    NG → REPLACE FLOOR WIRE 

    OK → See step   14 

  12. USE SIMULATION METHOD TO CHECK. Refer to  HOW TO PROCEED WITH TROUBLESHOOTING [10/2013 - ] 
  13. REPLACE AIRBAG ECU ASSEMBLY. Refer to  REMOVAL [10/2013 - ] 
  14. REPLACE FRONT SEAT INNER BELT ASSEMBLY LH. Refer to  REMOVAL [10/2013 - ] 
  15. REPLACE SEAT POSITION AIRBAG SENSOR. Refer to  REMOVAL [10/2013 - ]