Inspection Procedure

HINT:

• If troubleshooting (wire harness inspection) is difficult to perform, remove the front passenger seat installation bolts to see the under surface of the seat cushion.
• In the above case, hold the seat so that it does not fall down. Holding the seat for a long period of time may cause a problem, such as seat rail deformation. Hold the seat only as necessary.

1. CHECK DTC 
   1. Turn the ignition switch to the ON position.
   2. Clear the DTCs stored in the memory (See DTC CHECK / CLEAR  ).

      HINT:

      First clear DTCs stored in the occupant classification ECU and then in the center airbag sensor assembly.

   3. Turn the ignition switch to the LOCK position.
   4. Turn the ignition switch to the ON position.
   5. Check the DTCs (See DTC CHECK / CLEAR  ).

      OK: 

      DTC B1780 is not output. 

      HINT:

      Codes other than DTC B1780 may be output at this time, but they are not related to this check.

   OK: USE SIMULATION METHOD TO CHECK 

   NG: Go to next step 

2. CHECK CONNECTION OF CONNECTORS 
   1. Turn the ignition switch to the LOCK position.
   2. Disconnect the negative (-) terminal cable from the battery.
   3. Check that the connectors are properly connected to the occupant classification ECU and the front occupant classification sensor LH.

      OK: 

      The connectors are properly connected. 

   NG: CONNECT CONNECTORS 

   OK: Go to next step 

3. CHECK FRONT SEAT WIRE RH (SHORT TO B+) 
   Fig 1: Identifying Front Seat Wire RH (Short To B+)

   Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
   1. Disconnect the connectors from the occupant classification ECU and the front occupant classification sensor LH.
   2. Connect the negative (-) terminal cable to the battery.
   3. Turn the ignition switch to the ON position.
   4. Measure the voltage according to the value(s) in the table below.

      Standard voltage 

      TESTER CONNECTION SPECIFIED CONDITION
      
      

      Tester connection	Condition	Specified condition
      O5-1 (SGD1) - Body ground	Ignition switch ON	Below 1 V
      O5-7 (SIG1) - Body ground	Ignition switch ON	Below 1 V
      O5-11 (SVC1) - Body ground	Ignition switch ON	Below 1 V

   NG: REPAIR OR REPLACE FRONT SEAT WIRE RH 

   OK: Go to next step 

4. CHECK FRONT SEAT WIRE RH (OPEN) 
   Fig 2: Identifying Front Seat Wire RH (Open)

   Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
   1. Turn the ignition switch to the LOCK position.
   2. Disconnect the negative (-) terminal cable from the battery.
   3. Using a service wire, connect O6-1 (SVC1) and O6-3 (SGD1), and connect O6-2 (SIG1) and O6-3 (SGD1) of connector "C".
      NOTE: Do not forcibly insert a service wire into the terminals of the connector when connecting.
   4. Measure the resistance according to the value(s) in the table below.

      Standard resistance 

      TESTER CONNECTION SPECIFIED CONDITION
      
      

      Tester connection	Condition	Specified condition
      O5-7 (SIG1) - O5-1 (SGD1)	Always	Below 1 Ω
      O5-11 (SVC1) - O5-1 (SGD1)	Always	Below 1 Ω

   NG: REPAIR OR REPLACE FRONT SEAT WIRE RH 

   OK: Go to next step 

5. CHECK FRONT SEAT WIRE RH (SHORT) 
   Fig 3: Identifying Front Seat Wire RH (Short)

   Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
   1. Disconnect the service wire from connector "C".
   2. Measure the resistance according to the value(s) in the table below.

      Standard resistance 

      TESTER CONNECTION SPECIFIED CONDITION
      
      

      Tester connection	Condition	Specified condition
      O5-7 (SIG1) - O5-1 (SGD1)	Always	1 MΩ or higher
      O5-11 (SVC1) - O5-1 (SGD1)	Always	1 MΩ or higher
      O5-7 (SIG1) - O5-11 (SVC1)	Always	1 MΩ or higher

   NG: REPAIR OR REPLACE FRONT SEAT WIRE RH 

   OK: Go to next step 

6. CHECK FRONT SEAT WIRE RH (SHORT TO GROUND) 
   Fig 4: Identifying Front Seat Wire RH (Short To Ground)

   Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
   1. Measure the resistance according to the value(s) in the table below.

      Standard resistance 

      TESTER CONNECTION SPECIFIED CONDITION
      
      

      Tester connection	Condition	Specified condition
      O5-1 (SGD1) - Body ground	Always	1 MΩ or higher
      O5-7 (SIG1) - Body ground	Always	1 MΩ or higher
      O5-11 (SVC1) - Body ground	Always	1 MΩ or higher

   NG: REPAIR OR REPLACE FRONT SEAT WIRE RH 

   OK: Go to next step 

7. CHECK DTC 
   1. Connect the connectors to the occupant classification ECU and the front occupant classification sensor LH.
   2. Connect the negative (-) terminal cable to the battery.
   3. Turn the ignition switch to the ON position.
   4. Clear the DTCs stored in the memory (See DTC CHECK / CLEAR  ).

      HINT:

      First clear DTCs stored in the occupant classification ECU and then in the center airbag sensor assembly.

   5. Turn the ignition switch to the LOCK position.
   6. Turn the ignition switch to the ON position.
   7. Check the DTCs (See DTC CHECK / CLEAR  ).

      OK: 

      DTC B1780 is not output. 

      HINT:

      Codes other than DTC B1780 may be output at this time, but they are not related to this check.

   OK: USE SIMULATION METHOD TO CHECK 

   NG: Go to next step 

8. REPLACE OCCUPANT CLASSIFICATION ECU 
   1. Turn the ignition switch to the LOCK position.
   2. Disconnect the negative (-) terminal cable from the battery.
   3. Replace the occupant classification ECU (See REMOVAL  ).

      HINT:

      Perform the inspection using parts from a normal vehicle if possible.

   NEXT: Go to next step 

9. PERFORM ZERO POINT CALIBRATION 
   1. Connect the negative (-) terminal cable to the battery.
   2. Connect Techstream to the DLC3.
   3. Turn the ignition switch to the ON position.
   4. Using Techstream, perform "Zero point calibration" (See INITIALIZATION  ).

      OK: 

      "COMPLETED" is displayed. 

   NG:  Go to step  12

   OK: Go to next step 

10. PERFORM SENSITIVITY CHECK 
    1. Using Techstream, perform "Sensitivity check" (See INITIALIZATION  ).

       Standard value: 

       27 to 33 kg (59.52 to 72.75 lb) 

    NG:  Go to step  12

    OK: Go to next step 

11. CHECK DTC 
    1. Connect the negative (-) terminal cable to the battery.
    2. Turn the ignition switch to the ON position.
    3. Clear the DTCs stored in the memory (See DTC CHECK / CLEAR  ).

       HINT:

       First clear DTCs stored in the occupant classification ECU and then in the center airbag sensor assembly.

    4. Turn the ignition switch to the LOCK position.
    5. Turn the ignition switch to the ON position.
    6. Check the DTCs (See DTC CHECK / CLEAR  ).

       OK: 

       DTC B1780 is not output. 

       HINT:

       Codes other than DTC B1780 may be output at this time, but they are not related to this check.

    OK: END 

    NG: Go to next step 

12. REPLACE FRONT SEAT BACK ASSEMBLY RH 
    1. Turn the ignition switch to the LOCK position.
    2. Disconnect the negative (-) terminal cable from the battery.
    3. Replace the front seat back assembly RH (See DISASSEMBLY ).

    NEXT: Go to next step 

13. PERFORM ZERO POINT CALIBRATION 
    1. Connect the negative (-) terminal cable to the battery.
    2. Connect Techstream to the DLC3.
    3. Turn the ignition switch to the ON position.
    4. Using Techstream, perform "Zero point calibration" (See INITIALIZATION  ).

       OK: 

       "COMPLETED" is displayed. 

    NEXT: Go to next step 

14. PERFORM SENSITIVITY CHECK 
    1. Using Techstream, perform "Sensitivity check" (See INITIALIZATION  ).

       Standard value: 

       27 to 33 kg (59.52 to 72.75 lb) 

    NEXT : END