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DTC B1650/32: Occupant Classification System Malfunction: Procedure

  1. CHECK DTC (OCCUPANT CLASSIFICATION ECU) 
    1. Turn the power switch on (IG).
    2. Using the Techstream, check for DTCs of the occupant classification ECU. Refer to DTC CHECK / CLEAR .

    NG → See step   12 

    OK: Go to next step 

  2. CHECK CONNECTORS 
    1. Turn the power 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 center airbag sensor assembly and occupant classification ECU. Also check that the connectors that link the front seat wire RH and No. 2 floor wire are properly connected.

      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 center airbag sensor assembly and occupant classification ECU. Also disconnect the connectors that link the front seat wire RH and No. 2 floor wire.
    5. Check that the connector terminals are not damaged.

      OK

      The terminals are not deformed or damaged.

    NG → REPLACE WIRE HARNESS 

    OK: Go to next step 

  3. CHECK OCCUPANT CLASSIFICATION SYSTEM CIRCUIT (OPEN) 
    1. Connect the connectors that link the front seat wire RH and No. 2 floor wire.
      Fig 1: Identifying S1 And W3 Connector Terminals
      GTY233934Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
    2. Using SST, connect terminals 12 (FSR+) and 13 (FSR-) of connector B.
      NOTE:

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

      • SST: 09843-18040 
    3. Measure the resistance according to the value(s) in the table below.

      Standard Resistance

      Tester Connection Condition Specified Condition
      W3-8 (FSR+) - W3-4 (FSR-) Always Below 1 Ω
      TEXT IN ILLUSTRATION

      *1 Occupant Classification ECU *2 Center Airbag Sensor Assembly
      *3 Front view of wire harness connector
      (to Center Airbag Sensor Assembly)      		 *4 Front view of wire harness connector
      (to Occupant Classification ECU)
      *5 Connector B *6 Connector E

    NG → See step   7 

    OK: Go to next step 

  4. CHECK OCCUPANT CLASSIFICATION SYSTEM CIRCUIT (SHORT) 
    1. Disconnect SST from connector B.
      Fig 2: Identifying W3 Connector Terminals
      GTY214856Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
    2. Measure the resistance according to the value(s) in the table below.

      Standard Resistance

      Tester Connection Condition Specified Condition
      W3-8 (FSR+) - W3-4 (FSR-) Always 1 MΩ or higher
      TEXT IN ILLUSTRATION

      *1 Occupant Classification ECU
      *2 Center Airbag Sensor Assembly
      *3 Front view of wire harness connector
      (to Occupant Classification ECU)
      *4 Connector E

    NG → See step   8 

    OK: Go to next step 

  5. CHECK OCCUPANT CLASSIFICATION SYSTEM CIRCUIT (SHORT TO B+) 
    1. Connect the cable to the negative (-) battery terminal.
      Fig 3: Identifying W3 Connector Terminals
      GTY214856Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
    2. Turn the power switch on (IG).
    3. Measure the voltage according to the value(s) in the table below.

      Standard Voltage

      Tester Connection Switch Condition Specified Condition
      W3-8 (FSR+) - Body ground Power switch on (IG) Below 1 V
      W3-4 (FSR-) - Body ground Power switch on (IG) Below 1 V
      TEXT IN ILLUSTRATION

      *1 Occupant Classification ECU
      *2 Center Airbag Sensor Assembly
      *3 Front view of wire harness connector
      (to Occupant Classification ECU)
      *4 Connector E

    NG → See step   9 

    OK: Go to next step 

  6. CHECK OCCUPANT CLASSIFICATION SYSTEM CIRCUIT (SHORT TO GROUND) 
    1. Turn the power switch off.
      Fig 4: Identifying W3 Connector Terminals
      GTY214856Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
    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. Measure the resistance according to the value(s) in the table below.

      Standard Resistance

      Tester Connection Condition Specified Condition
      W3-8 (FSR+) - Body ground Always 1 MΩ or higher
      W3-4 (FSR-) - Body ground Always 1 MΩ or higher
      TEXT IN ILLUSTRATION

      *1 Occupant Classification ECU
      *2 Center Airbag Sensor Assembly
      *3 Front view of wire harness connector
      (to Occupant Classification ECU)
      *4 Connector E

      HINT: 

      After replacing the center airbag sensor assembly, check for DTCs of the center airbag sensor assembly. If DTC B1650/32 is detected, replace the occupant classification ECU. Refer to REMOVAL and perform "zero point calibration" and "sensitivity check" of the occupant classification system. Refer to INITIALIZATION .

    NG → See step   10 

    OK → See step   11 

  7. CHECK NO. 2 FLOOR WIRE (OPEN) 
    1. Disconnect the front seat wire RH from the No. 2 floor wire.
      Fig 5: Identifying S1 And SW1 Connector Terminals
      GTY234932Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

      HINT: 

      SST 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
      SW1-1 (FSR+) - SW1-4 (FSR-) Always Below 1 Ω
      TEXT IN ILLUSTRATION

      *1 Occupant Classification ECU *2 Center Airbag Sensor Assembly
      *3 Front Seat Wire RH *4 No. 2 Floor Wire
      *5 Front view of wire harness connector
      (to Center Airbag Sensor Assembly)      		 *6 Front view of wire harness connector
      (to Front Seat Wire RH)
      *7 Connector B *8 Connector C

    NG → REPLACE NO. 2 FLOOR WIRE 

    OK → REPLACE FRONT SEAT WIRE RH 

  8. CHECK NO. 2 FLOOR WIRE (SHORT) 
    1. Disconnect the front seat wire RH from the No. 2 floor wire.
      Fig 6: Identifying SW1 Connector Terminals
      GTY221606Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
    2. Measure the resistance according to the value(s) in the table below.

      Standard Resistance

      Tester Connection Condition Specified Condition
      SW1-1 (FSR+) - SW1-4 (FSR-) Always 1 MΩ or higher
      TEXT IN ILLUSTRATION

      *1 Occupant Classification ECU
      *2 Center Airbag Sensor Assembly
      *3 Front Seat Wire RH
      *4 No. 2 Floor Wire
      *5 Front view of wire harness connector
      (to Front Seat Wire RH)
      *6 Connector C

    NG → REPLACE NO. 2 FLOOR WIRE 

    OK → REPLACE FRONT SEAT WIRE RH 

  9. CHECK NO. 2 FLOOR WIRE (SHORT TO B+) 
    1. Turn the power switch off.
      Fig 7: Identifying SW1 Connector Terminals
      GTY221606Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
    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. Disconnect the front seat wire RH from the No. 2 floor wire.
    4. Connect the cable to the negative (-) battery terminal.
    5. Turn the power switch on (IG).
    6. Measure the voltage according to the value(s) in the table below.

      Standard Voltage

      Tester Connection Switch Condition Specified Condition
      SW1-1 (FSR+) - Body ground Power switch on (IG) Below 1 V
      SW1-4 (FSR-) - Body ground Power switch on (IG) Below 1 V
      TEXT IN ILLUSTRATION

      *1 Occupant Classification ECU
      *2 Center Airbag Sensor Assembly
      *3 Front Seat Wire RH
      *4 No. 2 Floor Wire
      *5 Front view of wire harness connector
      (to Front Seat Wire RH)
      *6 Connector C

    NG → REPLACE NO. 2 FLOOR WIRE 

    OK → REPLACE FRONT SEAT WIRE RH 

  10. CHECK NO. 2 FLOOR WIRE (SHORT TO GROUND) 
    1. Disconnect the front seat wire RH from the No. 2 floor wire.
      Fig 8: Identifying SW1 Connector Terminals
      GTY221606Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
    2. Measure the resistance according to the value(s) in the table below.

      Standard Resistance

      Tester Connection Condition Specified Condition
      SW1-1 (FSR+) - Body ground Always 1 MΩ or higher
      SW1-4 (FSR-) - Body ground Always 1 MΩ or higher
      TEXT IN ILLUSTRATION

      *1 Occupant Classification ECU
      *2 Center Airbag Sensor Assembly
      *3 Front Seat Wire RH
      *4 No. 2 Floor Wire
      *5 Front view of wire harness connector
      (to Front Seat Wire RH)
      *6 Connector C

    NG → REPLACE NO. 2 FLOOR WIRE 

    OK → REPLACE FRONT SEAT WIRE RH 

  11. REPLACE CENTER AIRBAG SENSOR ASSEMBLY. Refer to  REMOVAL 
  12. REPAIR CIRCUITS INDICATED BY OUTPUT DTCS. Refer to  DIAGNOSTIC TROUBLE CODE CHART 
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