AIRBAG SYSTEM, Diagnostic DTC:B1653/35

DTC Code DTC Name
B1653/35 Seat Position Airbag Sensor Circuit Malfunction

DESCRIPTION

The seat position airbag sensor circuit consists of the airbag sensor assembly, front seat inner belt assembly LH and seat position airbag sensor.

DTC B1653/35 is stored when a malfunction is detected in the seat position airbag sensor circuit.

DTC No. DTC Detection Condition Trouble Area
B1653/35

  • The airbag sensor assembly receives a line short circuit signal, an open circuit signal, a short circuit to ground signal or a short circuit to B+ signal in the seat position airbag sensor circuit.

  • Front seat inner belt assembly LH malfunction

  • Seat position airbag sensor malfunction

  • Airbag sensor assembly malfunction

  • Floor wire

  • Front seat inner belt assembly LH

  • Seat position airbag sensor

  • Airbag sensor assembly

WIRING DIAGRAM

A01G68RE03

INSPECTION PROCEDURE

Note

After turning the engine switch off, waiting time may be required before disconnecting the cable from the negative (-) battery terminal. Therefore, make sure to read the disconnecting the cable from the negative (-) battery terminal notices before proceeding with work Click here.

PROCEDURE


  1. CHECK CONNECTORS


    1. Turn the engine switch off.

    2. Disconnect the cable from the negative (-) battery terminal.

      CAUTION:

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

      OK
      The connectors are properly connected.

      Tech Tips

      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 connectors are not damaged.

      OK
      The terminals are not deformed or damaged.

    NG

    REPLACE WIRE HARNESS

    OK

  2. CHECK SEAT POSITION AIRBAG SENSOR CIRCUIT (OPEN)


    1. A01G8M4E01
      Text in Illustration
      *1 Seat Position Airbag Sensor
      *2 Airbag Sensor Assembly
      *3 Service Wire
      *a

      Front view of wire harness connector

      (to Airbag Sensor Assembly)
      *b

      Front view of wire harness connector

      (to Seat Position Airbag Sensor)

      Connect the connectors to the front seat inner belt assembly LH and floor wire.

    2. Using a service wire, connect terminals 9 (LSP+) and 17 (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
      2 (LSP+) - 1 (LSP-) Always Below 1 Ω

    NG

    CHECK FLOOR WIRE (OPEN) Click here

    OK

  3. CHECK SEAT POSITION AIRBAG SENSOR CIRCUIT (SHORT)


    1. A01G8QCE01
      Text in Illustration
      *1 Seat Position Airbag Sensor
      *2 Airbag Sensor Assembly
      *a

      Front view of wire harness connector

      (to Seat Position Airbag Sensor)

      Disconnect the service wire from connector B.

    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

    NG

    CHECK FLOOR WIRE (SHORT) Click here

    OK

  4. CHECK SEAT POSITION AIRBAG SENSOR CIRCUIT (SHORT TO B+)


    1. A01G8QCE01
      Text in Illustration
      *1 Seat Position Airbag Sensor
      *2 Airbag Sensor Assembly
      *a

      Front view of wire harness connector

      (to Seat Position Airbag Sensor)

      Connect the cable to the negative (-) battery terminal.

    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
      2 (LSP+) - Body ground Engine switch on (IG) Below 1 V
      1 (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.

      CAUTION:

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


    NG

    CHECK FLOOR WIRE (SHORT TO B+) Click here

    OK

  5. CHECK SEAT POSITION AIRBAG SENSOR CIRCUIT (SHORT TO GROUND)


    1. A01G8QCE01
      Text in Illustration
      *1 Seat Position Airbag Sensor
      *2 Airbag Sensor Assembly
      *a

      Front view of wire harness connector

      (to Seat Position Airbag Sensor)

      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

    NG

    CHECK FLOOR WIRE (SHORT TO GROUND) Click here

    OK

  6. CHECK DTC


    1. A01G6SHE01
      Text in Illustration
      *1 Seat Position Airbag Sensor
      *2 Airbag Sensor Assembly

      Connect the connectors to the airbag sensor assembly and seat position airbag sensor.

    2. Connect the cable to the negative (-) battery terminal.

    3. Clear the DTCs stored in memory Click here.

    4. Turn the engine switch off.

    5. Turn the engine switch on (IG), and wait for at least 60 seconds.

    6. Check for DTCs Click here.

      OK
      DTC B1653/35 is not output.

      Tech Tips

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

    7. Turn the engine switch off.


    NG

    CHECK SEAT POSITION AIRBAG SENSOR Click here

    OK

    USE SIMULATION METHOD TO CHECK Click here

  7. CHECK SEAT POSITION AIRBAG SENSOR


    1. A01G6SHE01
      Text in Illustration
      *1 Seat Position Airbag Sensor
      *2 Airbag Sensor Assembly

      Disconnect the cable from the negative (-) battery terminal.

      CAUTION:

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

    2. Replace the seat position airbag sensor with a known good one Click here.

      Tech Tips

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

    3. Connect the cable to the negative (-) battery terminal.

    4. Clear the DTCs stored in memory Click here.

    5. Turn the engine switch off.

    6. Turn the engine switch on (IG), and wait for at least 60 seconds.

    7. Check for DTCs Click here.

      OK
      DTC B1653/35 is not output.

      Tech Tips

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

    8. Turn the engine switch off.

    9. Disconnect the cable from the negative (-) battery terminal.

      CAUTION:

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

    10. Restore the seat position airbag sensor that was installed for testing to its original location Click here.


    NG

    REPLACE AIRBAG SENSOR ASSEMBLY Click here

    OK

    REPLACE SEAT POSITION AIRBAG SENSOR Click here

  8. CHECK FLOOR WIRE (OPEN)


    1. A01G6P2E01
      Text in Illustration
      *1 Seat Position Airbag Sensor
      *2 Airbag Sensor Assembly
      *3 Front Seat Inner Belt Assembly LH
      *4 Floor Wire
      *5 Service Wire
      *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)

      Disconnect the floor wire from the front seat inner belt assembly LH.

      Tech Tips

      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
      P20-4 (LSP+) - P20-3 (LSP-) Always Below 1 Ω

    3. Disconnect the service wire from the connector B.


    NG

    REPLACE FLOOR WIRE

    OK

    REPLACE FRONT SEAT INNER BELT ASSEMBLY LH Click here

  9. CHECK FLOOR WIRE (SHORT)


    1. A01G529E01
      Text in Illustration
      *1 Seat Position Airbag Sensor
      *2 Airbag Sensor 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)

      Disconnect the floor wire from the front seat inner belt assembly LH.

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      P20-4 (LSP+) - P20-3 (LSP-) Always 1 MΩ or higher

    NG

    REPLACE FLOOR WIRE

    OK

    REPLACE FRONT SEAT INNER BELT ASSEMBLY LH Click here

  10. CHECK FLOOR WIRE (SHORT TO B+)


    1. A01G529E01
      Text in Illustration
      *1 Seat Position Airbag Sensor
      *2 Airbag Sensor 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)

      Disconnect the floor wire from the front seat inner belt assembly LH.

    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
      P20-4 (LSP+) - Body ground Engine switch on (IG) Below 1 V
      P20-3 (LSP-) - Body ground Engine switch on (IG) Below 1 V

    NG

    REPLACE FLOOR WIRE

    OK

    REPLACE FRONT SEAT INNER BELT ASSEMBLY LH Click here

  11. CHECK FLOOR WIRE (SHORT TO GROUND)


    1. A01G529E01
      Text in Illustration
      *1 Seat Position Airbag Sensor
      *2 Airbag Sensor 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)

      Disconnect the floor wire from the front seat inner belt assembly LH.

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      P20-4 (LSP+) - Body ground Always 1 MΩ or higher
      P20-3 (LSP-) - Body ground Always 1 MΩ or higher

    NG

    REPLACE FLOOR WIRE

    OK

    REPLACE FRONT SEAT INNER BELT ASSEMBLY LH Click here