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DTC B1650/32: Occupant Classification System Malfunction: Procedure

  1. CHECK DTC (OCCUPANT DETECTION ECU) 
    1. Check for DTCs of the occupant detection ECU. Refer to DTC CHECK / CLEAR .

      OK

      DTC is not output.

    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 (-) auxiliary battery terminal.
      WARNING:

      Wait at least 90 seconds after disconnecting the cable from the negative (-) auxiliary battery terminal to disable the SRS system.

    3. Check that the connectors are properly connected to the airbag ECU assembly and occupant detection ECU. Also check that the connectors that link the No. 2 floor wire and front seat wire RH 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 airbag ECU assembly and occupant detection ECU. Also disconnect the connectors that link the No. 2 floor wire and front seat wire RH.
    5. Check that the terminals of the connectors 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 No. 2 floor wire and front seat wire RH.
      Fig 1: Checking Occupant Classification System Circuit For Open
      GTY330766Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
    2. Using a service wire, connect terminals 12 (FSR+) and 13 (FSR-) of connector B.
      NOTE:

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

    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 Detection ECU
      *2 Airbag ECU Assembly
      *3 Service Wire
      *a Front view of wire harness connector
      (to Airbag ECU Assembly)
      *b Front view of wire harness connector
      (to Occupant Detection ECU)

    NG → See step   7 

    OK: Go to next step 

  4. CHECK OCCUPANT CLASSIFICATION SYSTEM CIRCUIT (SHORT) 
    1. Disconnect the service wire from connector B.
      Fig 2: Checking Occupant Classification System Circuit For Short
      GTY323938Courtesy 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 Detection ECU
      *2 Airbag ECU Assembly
      *a Front view of wire harness connector
      (to Occupant Detection ECU)

    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 (-) auxiliary battery terminal.
      Fig 3: Checking Occupant Classification System Circuit For Short To B+
      GTY323938Courtesy 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 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
    4. Turn the power switch off.
    5. Disconnect the cable from the negative (-) auxiliary battery terminal.
      WARNING:

      Wait at least 90 seconds after disconnecting the cable from the negative (-) auxiliary battery terminal to disable the SRS system.

      TEXT IN ILLUSTRATION

      *1 Occupant Detection ECU
      *2 Airbag ECU Assembly
      *a Front view of wire harness connector
      (to Occupant Detection ECU)

    NG → See step   9 

    OK: Go to next step 

  6. CHECK OCCUPANT CLASSIFICATION SYSTEM CIRCUIT (SHORT TO GROUND) 
    1. Measure the resistance according to the value(s) in the table below.
      Fig 4: Checking Occupant Classification System Circuit For Short To Ground
      GTY323938Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

      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 Detection ECU
      *2 Airbag ECU Assembly
      *a Front view of wire harness connector
      (to Occupant Detection ECU)

    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: Checking No. 2 Floor Wire For Open
      GTY336048Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

      HINT: 

      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
      SW1-1 (FSR+) - SW1-4 (FSR-) Always Below 1 Ω
    3. Disconnect the service wire from connector B.
      TEXT IN ILLUSTRATION

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

    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: Checking No. 2 Floor Wire For Short
      GTY334336Courtesy 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 Detection ECU
      *2 Airbag ECU Assembly
      *3 Front Seat Wire RH
      *4 No. 2 Floor Wire
      *a Front view of wire harness connector
      (to Front Seat Wire RH)

    NG → REPLACE NO. 2 FLOOR WIRE 

    OK → REPLACE FRONT SEAT WIRE RH 

  9. CHECK NO. 2 FLOOR WIRE (SHORT TO B+) 
    1. Disconnect the front seat wire RH from the No. 2 floor wire.
      Fig 7: Checking No. 2 Floor Wire For Short To B+
      GTY334336Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
    2. Connect the cable to the negative (-) auxiliary battery terminal.
    3. Turn the power switch on (IG).
    4. Measure the voltage according to the value(s) in the table below.

      Standard Voltage

      Tester Connection 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 Detection ECU
      *2 Airbag ECU Assembly
      *3 Front Seat Wire RH
      *4 No. 2 Floor Wire
      *a Front view of wire harness connector
      (to Front Seat Wire RH)

    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: Checking No. 2 Floor Wire For Short To Ground
      GTY334336Courtesy 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 Detection ECU
      *2 Airbag ECU Assembly
      *3 Front Seat Wire RH
      *4 No. 2 Floor Wire
      *a Front view of wire harness connector
      (to Front Seat Wire RH)

    NG → REPLACE NO. 2 FLOOR WIRE 

    OK → REPLACE FRONT SEAT WIRE RH 

  11. REPLACE AIRBAG ECU ASSEMBLY. Refer to  REMOVAL 
  12. GO TO OCCUPANT CLASSIFICATION SYSTEM. Refer to  DIAGNOSTIC TROUBLE CODE CHART 
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