AIRBAG SYSTEM, Diagnostic DTC:B1666/81, B1667/81

DTC Code DTC Name
B1666/81 Lost Communication with Front Floor Airbag Sensor
B1667/81 Front Floor Airbag Sensor Initialization Incomplete

DESCRIPTION

The front floor side airbag sensor circuit consists of the airbag ECU assembly and front floor side airbag sensor.

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

DTC B1666/81 or B1667/81 is stored when a malfunction is detected in the front floor side airbag sensor circuit.

DTC No. Detection Item DTC Detection Condition Trouble Area
B1666/81 Lost Communication with Front Floor Airbag Sensor

One of the following conditions is met:


  • The airbag ECU assembly detects a line short circuit signal, open circuit signal, short circuit to ground signal or short circuit to B+ signal in the front floor side airbag sensor circuit for 2 seconds.

  • A front floor side airbag sensor malfunction.

  • An airbag ECU assembly malfunction.

  • Front floor side airbag sensor

  • Airbag ECU assembly

  • No. 2 floor wire
B1667/81 Front Floor Airbag Sensor Initialization Incomplete

One of the following conditions is met:


  • The airbag ECU assembly detects a line short circuit signal, open circuit signal, short circuit to ground signal or short circuit to B+ signal in the front floor side airbag sensor circuit for 2 seconds.

  • A front floor side airbag sensor malfunction.

  • An airbag ECU assembly malfunction.

  • Front floor side airbag sensor

  • Airbag ECU assembly

  • No. 2 floor wire

WIRING DIAGRAM

B006LTDE11

CAUTION / NOTICE / HINT

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

  • When disconnecting the cable from the negative (-) battery terminal while performing repairs, some systems need to be initialized after the cable is reconnected.

    Click here

  • After replacing the airbag ECU assembly, refer to initialization.

    Click here

PROCEDURE


  1. CHECK VEHICLE TYPE


    1. Check vehicle type.

      Result
      Proceed to
      for Front Console Box Integrated Type
      for Front Console Box Separate Type

    for Front Console Box Separate Type

    CHECK DTC Click here

    for Front Console Box Integrated Type

  2. CHECK DTC


    1. Turn the engine switch off.

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

    3. Check for DTCs.

      Click here


      Body Electrical > SRS Airbag > Trouble Codes
      Result
      Proceed to
      DTC B1666/81 or B1667/81 is output
      DTC B1666/81 and B1667/81 are not output

      Tech Tips

      Codes other than DTC B1666/81 and B1667/82 may be output at this time, but they are not related to this check.


    DTC B1666/81 and B1667/81 are not output

    USE SIMULATION METHOD TO CHECK Click here

    DTC B1666/81 or B1667/81 is output

  3. CHECK CONNECTION OF CONNECTORS


    1. Turn the engine switch off.

    2. Disconnect the cable from the negative (-) battery terminal, and wait for at least 90 seconds.

    3. Check that the connectors are properly connected to the airbag ECU assembly and front floor side airbag sensor.

      Result
      Proceed to
      The connectors are properly connected
      The connectors are not properly connected

    The connectors are not properly connected

    CONNECT CONNECTORS PROPERLY

    The connectors are properly connected

  4. CHECK CONNECTORS


    1. Disconnect the connectors from the airbag ECU assembly and front floor side airbag sensor.

    2. B006PWZC11
      *1 Front Floor Side Airbag Sensor
      *2 Airbag ECU Assembly
      *3 No. 2 Floor Wire

      Check that the connectors (on the airbag ECU assembly side and front airbag sensor side) are not damaged.

      Result
      Proceed to
      The connectors are not deformed or damaged
      The connectors are deformed or damaged

    The connectors are deformed or damaged

    REPLACE NO. 2 FLOOR WIRE

    The connectors are not deformed or damaged

  5. CHECK FRONT FLOOR SIDE AIRBAG SENSOR CIRCUIT


    1. Connect the cable to the negative (-) battery terminal, and wait for at least 2 seconds.

      B006LRDC03
      *1 Front Floor Side Airbag Sensor *2 Airbag ECU Assembly
      *3 No. 2 Floor Wire *4 Connector C
      *5 Connector B *6 Service Wire
      *a

      Front view of wire harness connector

      (to Front Floor Side Airbag Sensor)

      		 *b

      Rear view of wire harness connector

      (to Airbag ECU Assembly)

    2. Turn the engine switch on (IG).

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

      Standard Voltage
      Tester Connection Switch Condition Specified Condition
      L13-2 (BFR+) - Body ground Engine switch on (IG) Below 1 V
      L13-1 (BFR-) - Body ground Engine switch on (IG) Below 1 V

    4. Turn the engine switch off.

    5. Disconnect the cable from the negative (-) battery terminal, and wait for at least 90 seconds.

    6. Using a service wire, connect terminals 20 (BCR+) and 19 (BCR-) of connector B.

      Note

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

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      L13-2 (BFR+) - L13-1 (BFR-) Always Below 1 Ω

    8. Disconnect the service wire from connector B.

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      L13-2 (BFR+) - L13-1 (BFR-) Always 1 MΩ or higher
      L13-2 (BFR+) - Body ground Always 1 MΩ or higher
      L13-1 (BFR-) - Body ground Always 1 MΩ or higher
      Result
      Proceed to
      OK
      NG

    NG

    REPLACE NO. 2 FLOOR WIRE

    OK

  6. CHECK FRONT FLOOR SIDE AIRBAG SENSOR


    1. B006KW2C26
      *1 Front Floor Side Airbag Sensor
      *2 Airbag ECU Assembly

      Connect the connectors to the airbag ECU assembly.

    2. Interchange the front floor side airbag sensor with a new one and connect the connectors to it.

    3. Connect the cable to the negative (-) battery terminal, and wait for at least 2 seconds.

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

    5. Clear the DTCs stored in memory.

      Click here


      Body Electrical > SRS Airbag > Clear DTCs

    6. Turn the engine switch off.

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

    8. Check for DTCs.

      Click here


      Body Electrical > SRS Airbag > Trouble Codes
      Result
      Proceed to
      DTC B1666/81 or B1667/81 is output
      DTC B1666/81 and B1667/81 are not output

      Tech Tips

      Codes other than DTC B1666/81 and B1667/81 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, and wait for at least 90 seconds.

    11. Return the front floor side airbag sensor to its original position and connect the connectors to it.


    DTC B1666/81 or B1667/81 is output

    REPLACE AIRBAG ECU ASSEMBLY w/ Navigation System: REPLACE AIRBAG ECU ASSEMBLY Click here
    REPLACE AIRBAG ECU ASSEMBLY w/o Navigation System: REPLACE AIRBAG ECU ASSEMBLY Click here

    DTC B1666/81 and B1667/81 are not output

    END (FRONT FLOOR SIDE AIRBAG SENSOR WAS DEFECTIVE)

  7. CHECK DTC


    1. Turn the engine switch off.

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

    3. Check for DTCs.

      Click here


      Body Electrical > SRS Airbag > Trouble Codes
      Result
      Proceed to
      DTC B1666/81 or B1667/81 is output
      DTC B1666/81 and B1667/81 are not output

      Tech Tips

      Codes other than DTC B1666/81 and B1667/82 may be output at this time, but they are not related to this check.


    DTC B1666/81 and B1667/81 are not output

    USE SIMULATION METHOD TO CHECK Click here

    DTC B1666/81 or B1667/81 is output

  8. CHECK CONNECTION OF CONNECTORS


    1. Turn the engine switch off.

    2. Disconnect the cable from the negative (-) battery terminal, and wait for at least 90 seconds.

    3. Check that the connectors are properly connected to the airbag ECU assembly and front floor side airbag sensor.

      Result
      Proceed to
      The connectors are properly connected
      The connectors are not properly connected

    The connectors are not properly connected

    CONNECT CONNECTORS PROPERLY

    The connectors are properly connected

  9. CHECK CONNECTORS


    1. Disconnect the connectors from the airbag ECU assembly and front floor side airbag sensor.

    2. B006PWZC11
      *1 Front Floor Side Airbag Sensor
      *2 Airbag ECU Assembly
      *3 No. 2 Floor Wire

      Check that the connectors (on the airbag ECU assembly side and front airbag sensor side) are not damaged.

      Result
      Proceed to
      The connectors are not deformed or damaged
      The connectors are deformed or damaged

    The connectors are deformed or damaged

    REPLACE NO. 2 FLOOR WIRE

    The connectors are not deformed or damaged

  10. CHECK FRONT FLOOR SIDE AIRBAG SENSOR CIRCUIT


    1. Connect the cable to the negative (-) battery terminal, and wait for at least 2 seconds.

      B006LRDC04
      *1 Front Floor Side Airbag Sensor *2 Airbag ECU Assembly
      *3 No. 2 Floor Wire *4 Connector C
      *5 Connector B *6 Service Wire
      *a

      Front view of wire harness connector

      (to Front Floor Side Airbag Sensor)

      		 *b

      Rear view of wire harness connector

      (to Airbag ECU Assembly)

    2. Turn the engine switch on (IG).

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

      Standard Voltage
      Tester Connection Switch Condition Specified Condition
      L10-2 (BFR+) - Body ground Engine switch on (IG) Below 1 V
      L10-1 (BFR-) - Body ground Engine switch on (IG) Below 1 V

    4. Turn the engine switch off.

    5. Disconnect the cable from the negative (-) battery terminal, and wait for at least 90 seconds.

    6. Using a service wire, connect terminals 20 (BCR+) and 19 (BCR-) of connector B.

      Note

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

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      L10-2 (BFR+) - L10-1 (BFR-) Always Below 1 Ω

    8. Disconnect the service wire from connector B.

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      L10-2 (BFR+) - L10-1 (BFR-) Always 1 MΩ or higher
      L10-2 (BFR+) - Body ground Always 1 MΩ or higher
      L10-1 (BFR-) - Body ground Always 1 MΩ or higher
      Result
      Proceed to
      OK
      NG

    NG

    REPLACE NO. 2 FLOOR WIRE

    OK

  11. CHECK FRONT FLOOR SIDE AIRBAG SENSOR


    1. B006KW2C26
      *1 Front Floor Side Airbag Sensor
      *2 Airbag ECU Assembly

      Connect the connectors to the airbag ECU assembly.

    2. Interchange the front floor side airbag sensor with a new one and connect the connectors to it.

    3. Connect the cable to the negative (-) battery terminal, and wait for at least 2 seconds.

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

    5. Clear the DTCs stored in memory.

      Click here


      Body Electrical > SRS Airbag > Clear DTCs

    6. Turn the engine switch off.

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

    8. Check for DTCs.

      Click here


      Body Electrical > SRS Airbag > Trouble Codes
      Result
      Proceed to
      DTC B1666/81 or B1667/81 is output
      DTC B1666/81 and B1667/81 are not output

      Tech Tips

      Codes other than DTC B1666/81 and B1667/81 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, and wait for at least 90 seconds.

    11. Return the front floor side airbag sensor to its original position and connect the connectors to it.


    DTC B1666/81 or B1667/81 is output

    REPLACE AIRBAG ECU ASSEMBLY w/ Navigation System: REPLACE AIRBAG ECU ASSEMBLY Click here
    REPLACE AIRBAG ECU ASSEMBLY w/o Navigation System: REPLACE AIRBAG ECU ASSEMBLY Click here

    DTC B1666/81 and B1667/81 are not output

    END (FRONT FLOOR SIDE AIRBAG SENSOR WAS DEFECTIVE)