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Home >> Scion >> 2014 >> FR-S Standard Trans >> Repair and Diagnosis (Single Page) >> Restraints >> Air Bag, SRS >> Supplemental Restraint System (Diagnostic Codes & Symptom Tests) >> Airbag System >> DTC B1678: Lost Communication with Rear Floor Airbag Sensor LH; DTC B1679: Rear Floor Airbag Sensor LH Initialization Incomplete >> Procedure

DTC B1678: Lost Communication with Rear Floor Airbag Sensor LH; DTC B1679: Rear Floor Airbag Sensor LH Initialization Incomplete: Procedure

  1. CHECK CONNECTORS 
    1. Turn the ignition 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 and No. 2 airbag sensor assembly.

      OK

      The connectors are properly connected.

      HINT: 

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

    4. Disconnect the connectors from the airbag ECU assembly and No. 2 airbag sensor assembly.
    5. Check that the terminals of connectors are not damaged.

      OK

      The connectors are not deformed or damaged.

    NG → REPLACE FLOOR WIRE 

    OK: Go to next step 

  2. CHECK FLOOR WIRE (OPEN) 
    1. Using a service wire, connect terminals 11 (BBL2+) and 12 (BBL2-) of connector B.
      GTY391084Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
      NOTE:

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

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

      Standard Resistance

      Tester Connection Condition Specified Condition
      H16-1 (BBL2-) - H16-2 (BBL2+) Always Below 1 Ω
    3. Disconnect the service wire from connector B.
      TEXT IN ILLUSTRATION

      *1 No. 2 Airbag Sensor Assembly
      *2 Airbag ECU Assembly
      *3 Floor Wire
      *4 Service Wire
      *a Front view of wire harness connector
      (to Airbag ECU Assembly)
      *b Front view of wire harness connector
      (to No. 2 Airbag Sensor Assembly)

    NG → REPLACE FLOOR WIRE 

    OK: Go to next step 

  3. CHECK FLOOR WIRE (SHORT) 
    1. Measure the resistance according to the value(s) in the table below.
      GTY388952Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

      Standard Resistance

      Tester Connection Condition Specified Condition
      H16-1 (BBL2-) - H16-2 (BBL2+) Always 1 MΩ or higher
      TEXT IN ILLUSTRATION

      *1 No. 2 Airbag Sensor Assembly
      *2 Airbag ECU Assembly
      *3 Floor Wire
      *a Front view of wire harness connector
      (to No. 2 Airbag Sensor Assembly)

    NG → REPLACE FLOOR WIRE 

    OK: Go to next step 

  4. CHECK FLOOR WIRE (SHORT TO B+) 
    1. Connect the cable to the negative (-) battery terminal.
      GTY388952Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
    2. Turn the ignition switch to ON.
    3. Measure the voltage according to the value(s) in the table below.

      Standard Voltage

      Tester Connection Condition Specified Condition
      H16-1 (BBL2-) - Body ground Ignition switch ON Below 1 V
      H16-2 (BBL2+) - Body ground Ignition switch ON Below 1 V
    4. Turn the ignition 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 No. 2 Airbag Sensor Assembly
      *2 Airbag ECU Assembly
      *3 Floor Wire
      *a Front view of wire harness connector
      (to No. 2 Airbag Sensor Assembly)

    NG → REPLACE FLOOR WIRE 

    OK: Go to next step 

  5. CHECK FLOOR WIRE (SHORT TO GROUND) 
    1. Measure the resistance according to the value(s) in the table below.
      GTY388952Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

      Standard Resistance

      Tester Connection Condition Specified Condition
      H16-1 (BBL2-) - Body ground Always 1 MΩ or higher
      H16-2 (BBL2+) - Body ground Always 1 MΩ or higher
      TEXT IN ILLUSTRATION

      *1 No. 2 Airbag Sensor Assembly
      *2 Airbag ECU Assembly
      *3 Floor Wire
      *a Front view of wire harness connector
      (to No. 2 Airbag Sensor Assembly)

    NG → REPLACE FLOOR WIRE 

    OK: Go to next step 

  6. CHECK NO. 2 AIRBAG SENSOR ASSEMBLY 
    1. Connect the connectors to the No. 2 airbag sensor assembly and airbag ECU assembly.
      GTY315873Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
    2. Replace the No. 2 airbag sensor assembly with a new one.
    3. Connect the cable to the negative (-) battery terminal.
    4. Clear the DTCs stored in memory. Refer to DTC CHECK / CLEAR [07/2013 - ] .
    5. Turn the ignition switch off.
    6. Turn the ignition switch to ON, and wait for at least 60 seconds.
    7. Check for DTCs. Refer to DTC CHECK / CLEAR [07/2013 - ] .
      Result Proceed to
      DTCs B1678 and B1679 are not output. A
      DTC B1678 or B1679 is output. B

      HINT: 

      Codes other than DTCs B1678 and B1679 may be output at this time, but they are not related to this check.

      TEXT IN ILLUSTRATION

      *1 No. 2 Airbag Sensor Assembly
      *2 Airbag ECU Assembly

    B → See step   7 

    A → END (NO. 2 AIRBAG SENSOR ASSEMBLY WAS DEFECTIVE) 

  7. REPLACE AIRBAG ECU ASSEMBLY. Refer to  REMOVAL [07/2013 - 12/2013] 
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