AIRBAG SYSTEM, Diagnostic DTC:B1676/85, B1677/85

DTC Code DTC Name
B1676/85 Lost Communication with Rear Floor Airbag Sensor RH
B1677/85 Rear Floor Airbag Sensor RH Initialization Incomplete

DESCRIPTION

Tech Tips

"Rear floor side airbag sensor RH" refers to the rear floor side airbag sensor.

The rear floor side airbag sensor circuit consists of the center airbag sensor and rear floor side airbag sensor.

The rear floor side airbag sensor detects impacts to the vehicle and sends signals to the center airbag sensor to determine if the airbag should be deployed.

DTC B1676/85 or B1677/85 is stored when a malfunction is detected in the rear floor side airbag sensor circuit

DTC Code DTC Detection Condition Trouble Area
B1676/85

One of the following conditions is met:


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

  • A rear floor side airbag sensor malfunction.

  • A center airbag sensor malfunction.

  • Floor wire

  • Rear floor side airbag sensor

  • Center airbag sensor assembly
B1677/85

One of the following conditions is met:


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

  • A rear floor side airbag sensor malfunction.

  • A center airbag sensor malfunction.

  • Floor wire

  • Rear floor side airbag sensor

  • Center airbag sensor assembly

WIRING DIAGRAM

B001FDBE06
*a Rear Floor Side Airbag Sensor
*b Center Airbag Sensor

CAUTION / NOTICE / HINT

Note


  • After turning the ignition switch off, waiting time may be required before disconnecting the cable from the battery terminal. Therefore, make sure to read the disconnecting the cable from the battery terminal notice 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.

PROCEDURE


  1. CHECK CONNECTION OF CONNECTORS


    1. Turn the ignition 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 center airbag sensor and rear floor side airbag sensor.

      OK
      The connectors are properly connected.

    NG

    CONNECT CONNECTORS PROPERLY

    OK

  2. CHECK CONNECTORS


    1. Disconnect the connectors from the center airbag sensor and rear floor side airbag sensor.

    2. B001EH3E01
      Text in Illustration
      *1 Rear Floor Side Airbag Sensor
      *2 Center Airbag Sensor

      Check that the connectors (on the center airbag sensor side and rear floor side airbag sensor side) are not damaged.

      OK
      The connectors are not deformed or damaged.

    NG

    REPLACE FLOOR WIRE

    OK

  3. CHECK REAR FLOOR SIDE AIRBAG SENSOR CIRCUIT


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

      B001G08E01
      Text in Illustration
      *1 Rear Floor Side Airbag Sensor *2 Center Airbag Sensor
      *3 Floor Wire *4 Connector C
      *5 Connector B *6 Service Wire
      *a

      Front view of wire harness connector

      (to Rear Floor Side Airbag Sensor)

      		 *b

      Rear view of wire harness connector

      (to Center Airbag Sensor)

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

      Standard Voltage
      Tester Connection Switch Condition Specified Condition
      Q5-2 (BER+) - Body ground Ignition switch ON Below 1 V
      Q5-1 (BER-) - Body ground Ignition switch ON Below 1 V

    3. Turn the ignition switch off.

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

    5. Using a service wire, connect terminals 15 (BCR+) and 14 (BCR-) of connector B.

      Note

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

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      Q5-2 (BER+) - Q5-1 (BER-) Always Below 1 Ω

    7. Disconnect the service wire from connector B.

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      Q5-2 (BER+) - Q5-1 (BER-) Always 1 MΩ or higher
      Q5-2 (BER+) - Body ground Always 1 MΩ or higher
      Q5-1 (BER-) - Body ground Always 1 MΩ or higher

    NG

    REPLACE FLOOR WIRE

    OK

  4. CHECK REAR FLOOR SIDE AIRBAG SENSOR


    1. B001F4DE03
      Text in Illustration
      *1 Rear Floor Side Airbag Sensor
      *2 Center Airbag Sensor

      Connect the connectors to the center airbag sensor.

    2. Temporarily replace the rear floor side airbag sensor with a new one.

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

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

    5. Clear the DTCs stored in 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.

      OK
      DTC B1676 and B1677 are not output.

      Tech Tips

      Codes other than DTC B1676 and B1677 may be output at this time, but they are not related to this check.


    OK

    REPLACE REAR FLOOR SIDE AIRBAG SENSOR Click here

    NG

    REPLACE CENTER AIRBAG SENSOR ASSEMBLY Click here