AIRBAG SYSTEM, Diagnostic DTC:B161C/9A, B161D/9A

DTC Code DTC Name
B161C/9A Lost Communication with Front Satellite Sensor Bus Center
B161D/9A Front Satellite Sensor Bus Center Initialization Incomplete

DESCRIPTION

The front airbag sensor circuit consists of the center airbag sensor assembly and front airbag sensor.

The front airbag sensor detects impacts to the vehicle and sends signals to the center airbag sensor assembly to determine if the airbag should be deployed.

These DTCs are stored when a malfunction is detected in the front airbag sensor circuit.

DTC No. DTC Detection Condition Trouble Area

B161C/9A

B161D/9A

  • The center 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 front airbag sensor circuit.

  • Front airbag sensor malfunction

  • Center airbag sensor assembly malfunction

  • Instrument panel wire

  • Engine room main wire

  • Front airbag sensor

  • Center airbag sensor assembly

WIRING DIAGRAM

A005GKSE24
*a FRONT AIRBAG SENSOR
*b CENTER AIRBAG SENSOR ASSEMBLY

PROCEDURE


  1. CHECK CONNECTORS


    1. Turn the ignition 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 center airbag sensor assembly and front airbag sensor. Also check that the connectors that link the engine room main wire and instrument panel wire are properly connected.

      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 center airbag sensor assembly and front airbag sensor. Also disconnect the connectors that link the engine room main wire and instrument panel wire.

    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 FRONT AIRBAG SENSOR CIRCUIT (OPEN)


    1. w/o VSC


      1. Connect the connectors that link the engine room main wire and instrument panel wire.

        A005J1OE02
        Text in Illustration
        *1 Front Airbag Sensor *2 Center Airbag Sensor Assembly
        *3 Connector B *4 Connector E
        *5 Service Wire - -
        *a

        Rear view of wire harness connector

        (to Center Airbag Sensor Assembly)

        		 *b

        Front view of wire harness connector

        (to Front Airbag Sensor)

      2. Using a service wire, connect terminals 30 (+SL) and 28 (-SL) of connector B.

        Note

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

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

        Standard Resistance
        Tester Connection Condition Specified Condition
        A20-2 (+SL) - A20-1 (-SL) Always Below 1 Ω

    2. w/ VSC


      1. Connect the connectors that link the engine room main wire and instrument panel wire.

        A005KJPE02
        Text in Illustration
        *1 Front Airbag Sensor *2 Center Airbag Sensor Assembly
        *3 Connector B *4 Connector E
        *5 Service Wire - -
        *a

        Rear view of wire harness connector

        (to Center Airbag Sensor Assembly)

        		 *b

        Front view of wire harness connector

        (to Front Airbag Sensor)

      2. Using a service wire, connect terminals 30 (+SL) and 28 (-SL) of connector B.

        Note

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

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

        Standard Resistance
        Tester Connection Condition Specified Condition
        A20-2 (+SL) - A20-1 (-SL) Always Below 1 Ω

    NG

    CHECK INSTRUMENT PANEL WIRE (OPEN) Click here

    OK

  3. CHECK FRONT AIRBAG SENSOR CIRCUIT (SHORT)


    1. w/o VSC


      1. A005KC4E01
        Text in Illustration
        *1 Front Airbag Sensor
        *2 Center Airbag Sensor Assembly
        *3 Connector E
        *a

        Front view of wire harness connector

        (to Front 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
        A20-2 (+SL) - A20-1 (-SL) Always 1 MΩ or higher

    2. w/ VSC


      1. A005MJEE01
        Text in Illustration
        *1 Front Airbag Sensor
        *2 Center Airbag Sensor Assembly
        *3 Connector E
        *a

        Front view of wire harness connector

        (to Front 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
        A20-2 (+SL) - A20-1 (-SL) Always 1 MΩ or higher

    NG

    CHECK INSTRUMENT PANEL WIRE (SHORT) Click here

    OK

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


    1. w/o VSC


      1. A005IOHE01
        Text in Illustration
        *1 Front Airbag Sensor
        *2 Center Airbag Sensor Assembly
        *3 Connector E
        *a

        Front view of wire harness connector

        (to Front Airbag Sensor)

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

      2. Turn the ignition switch to ON.

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

        Standard Voltage
        Tester Connection Switch Condition Specified Condition
        A20-2 (+SL) - Body ground Ignition switch ON Below 1 V
        A20-1 (-SL) - Body ground Ignition switch ON Below 1 V

    2. w/ VSC


      1. A005MJEE01
        Text in Illustration
        *1 Front Airbag Sensor
        *2 Center Airbag Sensor Assembly
        *3 Connector E
        *a

        Front view of wire harness connector

        (to Front Airbag Sensor)

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

      2. Turn the ignition switch to ON.

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

        Standard Voltage
        Tester Connection Switch Condition Specified Condition
        A20-2 (+SL) - Body ground Ignition switch ON Below 1 V
        A20-1 (-SL) - Body ground Ignition switch ON Below 1 V

    NG

    CHECK INSTRUMENT PANEL WIRE (SHORT TO B+) Click here

    OK

  5. CHECK FRONT AIRBAG SENSOR CIRCUIT (SHORT TO GROUND)


    1. w/o VSC


      1. A005IOHE01
        Text in Illustration
        *1 Front Airbag Sensor
        *2 Center Airbag Sensor Assembly
        *3 Connector E
        *a

        Front view of wire harness connector

        (to Front Airbag Sensor)

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

        Standard Resistance
        Tester Connection Condition Specified Condition
        A20-2 (+SL) - Body ground Always 1 MΩ or higher
        A20-1 (-SL) - Body ground Always 1 MΩ or higher

    2. w/ VSC


      1. A005MJEE01
        Text in Illustration
        *1 Front Airbag Sensor
        *2 Center Airbag Sensor Assembly
        *3 Connector E
        *a

        Front view of wire harness connector

        (to Front Airbag Sensor)

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

        Standard Resistance
        Tester Connection Condition Specified Condition
        A20-2 (+SL) - Body ground Always 1 MΩ or higher
        A20-1 (-SL) - Body ground Always 1 MΩ or higher

    NG

    CHECK INSTRUMENT PANEL WIRE (SHORT TO GROUND) Click here

    OK

  6. CHECK FRONT AIRBAG SENSOR


    1. Connect the connector to the center airbag sensor assembly.

    2. Temporarily replace the front airbag sensor with a new one.

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

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

    5. Clear the DTCs stored in the memory Click here.

    6. Turn the ignition switch off.

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

    8. Check for DTCs Click here.

      Result
      Result Proceed to
      DTC B161C/9A or B161D/9A is not output. A
      DTC B161C/9A or B161D/9A is output. B

      Tech Tips

      Codes other than DTCs B161C/9A and B161D/9A may be output at this time, but they are not related to this check.


    A

    USE SIMULATION METHOD TO CHECK Click here

    B

    REPLACE CENTER AIRBAG SENSOR ASSEMBLY Click here

  7. CHECK INSTRUMENT PANEL WIRE (OPEN)


    1. w/o VSC


      1. Disconnect the instrument panel wire connector from the engine room main wire.

        A005IL5E02
        Text in Illustration
        *1 Front Airbag Sensor *2 Center Airbag Sensor Assembly
        *3 Engine Room Main Wire *4 Instrument Panel Wire
        *5 Connector B *6 Connector C
        *7 Service Wire - -
        *a

        Rear view of wire harness connector

        (to Center Airbag Sensor Assembly)

        		 *b

        Front view of wire harness connector

        (to Engine Room Main Wire)

        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
        AF1-1 (+SL) - AF1-2 (-SL) Always Below 1 Ω

    2. w/ VSC


      1. Disconnect the instrument panel wire connector from the engine room main wire.

        A005J9ME02
        Text in Illustration
        *1 Front Airbag Sensor *2 Center Airbag Sensor Assembly
        *3 Engine Room Main Wire *4 Instrument Panel Wire
        *5 Connector B *6 Connector C
        *7 Service Wire - -
        *a

        Rear view of wire harness connector

        (to Center Airbag Sensor Assembly)

        		 *b

        Front view of wire harness connector

        (to Engine Room Main Wire)

        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
        AF1-1 (+SL) - AF1-2 (-SL) Always Below 1 Ω

    OK

    REPLACE ENGINE ROOM MAIN WIRE

    NG

    REPLACE INSTRUMENT PANEL WIRE

  8. CHECK INSTRUMENT PANEL WIRE (SHORT)


    1. w/o VSC


      1. A005I39E02
        Text in Illustration
        *1 Front Airbag Sensor
        *2 Center Airbag Sensor Assembly
        *3 Engine Room Main Wire
        *4 Instrument Panel Wire
        *5 Connector C
        *a

        Front view of wire harness connector

        (to Engine Room Main Wire)

        Disconnect the instrument panel wire connector from the engine room main wire.

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

        Standard Resistance
        Tester Connection Condition Specified Condition
        AF1-1 (+SL) - AF1-2 (-SL) Always 1 MΩ or higher

    2. w/ VSC


      1. A005KS0E02
        Text in Illustration
        *1 Front Airbag Sensor
        *2 Center Airbag Sensor Assembly
        *3 Engine Room Main Wire
        *4 Instrument Panel Wire
        *5 Connector C
        *a

        Front view of wire harness connector

        (to Engine Room Main Wire)

        Disconnect the instrument panel wire connector from the engine room main wire.

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

        Standard Resistance
        Tester Connection Condition Specified Condition
        AF1-1 (+SL) - AF1-2 (-SL) Always 1 MΩ or higher

    OK

    REPLACE ENGINE ROOM MAIN WIRE

    NG

    REPLACE INSTRUMENT PANEL WIRE

  9. CHECK INSTRUMENT PANEL WIRE (SHORT TO B+)


    1. w/o VSC


      1. A005I39E02
        Text in Illustration
        *1 Front Airbag Sensor
        *2 Center Airbag Sensor Assembly
        *3 Engine Room Main Wire
        *4 Instrument Panel Wire
        *5 Connector C
        *a

        Front view of wire harness connector

        (to Engine Room Main Wire)

        Turn the ignition 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. Disconnect the instrument panel wire connector from the engine room main wire.

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

      5. Turn the ignition switch to ON.

      6. Measure the voltage according to the value(s) in the table below.

        Standard Voltage
        Tester Connection Switch Condition Specified Condition
        AF1-1 (+SL) - Body ground Ignition switch ON Below 1 V
        AF1-2 (-SL) - Body ground Ignition switch ON Below 1 V

    2. w/ VSC


      1. A005KS0E02
        Text in Illustration
        *1 Front Airbag Sensor
        *2 Center Airbag Sensor Assembly
        *3 Engine Room Main Wire
        *4 Instrument Panel Wire
        *5 Connector C
        *a

        Front view of wire harness connector

        (to Engine Room Main Wire)

        Turn the ignition 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. Disconnect the instrument panel wire connector from the engine room main wire.

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

      5. Turn the ignition switch to ON.

      6. Measure the voltage according to the value(s) in the table below.

        Standard Voltage
        Tester Connection Switch Condition Specified Condition
        AF1-1 (+SL) - Body ground Ignition switch ON Below 1 V
        AF1-2 (-SL) - Body ground Ignition switch ON Below 1 V

    OK

    REPLACE ENGINE ROOM MAIN WIRE

    NG

    REPLACE INSTRUMENT PANEL WIRE

  10. CHECK INSTRUMENT PANEL WIRE (SHORT TO GROUND)


    1. w/o VSC


      1. A005I39E02
        Text in Illustration
        *1 Front Airbag Sensor
        *2 Center Airbag Sensor Assembly
        *3 Engine Room Main Wire
        *4 Instrument Panel Wire
        *5 Connector C
        *a

        Front view of wire harness connector

        (to Engine Room Main Wire)

        Disconnect the instrument panel wire connector from the engine room main wire.

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

        Standard Resistance
        Tester Connection Condition Specified Condition
        AF1-1 (+SL) - Body ground Always 1 MΩ or higher
        AF1-2 (-SL) - Body ground Always 1 MΩ or higher

    2. w/ VSC


      1. A005KS0E02
        Text in Illustration
        *1 Front Airbag Sensor
        *2 Center Airbag Sensor Assembly
        *3 Engine Room Main Wire
        *4 Instrument Panel Wire
        *5 Connector C
        *a

        Front view of wire harness connector

        (to Engine Room Main Wire)

        Disconnect the instrument panel wire connector from the engine room main wire.

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

        Standard Resistance
        Tester Connection Condition Specified Condition
        AF1-1 (+SL) - Body ground Always 1 MΩ or higher
        AF1-2 (-SL) - Body ground Always 1 MΩ or higher

    OK

    REPLACE ENGINE ROOM MAIN WIRE

    NG

    REPLACE INSTRUMENT PANEL WIRE