Inspection Procedure

HINT:

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

1. CHECK FOR DTC 
   1. Turn the ignition switch to ON.
   2. Clear the DTCs (see DIAGNOSIS SYSTEM  ).

      HINT:

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

   3. Turn the ignition switch off.
   4. Turn the ignition switch to ON.
   5. Check the DTCs (see DIAGNOSIS SYSTEM  ).

      OK: 

      DTC B1781 is not output. 

      HINT:

      DTCs other than DTC B1781 may be output at this time, but they are not related to this check.

      OK: Go to next step 

      NG: USE SIMULATION METHOD TO CHECK 

2. CHECK CONNECTION OF CONNECTOR 
   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 occupant classification ECU and the front occupant classification sensor RH.

      OK: 

      The connectors are properly connected. 

      NG: CONNECT CONNECTOR 

      OK: Go to next step 

3. CHECK FRONT SEAT WIRE RH (TO B+) 
   1. Disconnect the connectors from the occupant classification ECU and the front occupant classification sensor RH.
   2. Connect the cable to the negative (-) battery terminal, and wait for at least 2 seconds.
   3. Turn the ignition switch to ON.
   4. Measure the voltage of the wire harness side connector.

      Standard voltage 

      VOLTAGE SPECIFIED CONDITION
      
      

      Tester Connection	Specified Condition
      a1-2 (SGD2) - Body ground	Below 1 V
      a1-8 (SIG2) - Body ground	Below 1 V
      a1-12 (SVC2) - Body ground	Below 1 V

      NG: REPAIR OR REPLACE FRONT SEAT WIRE RH 

      Fig 1: Checking Front Seat Wire RH (To B+)

      Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

      OK: Go to next step 

4. CHECK FRONT SEAT WIRE RH (FOR OPEN) 
   1. Turn the ignition switch off.
   2. Disconnect the cable from the negative (-) battery terminal, and wait for at least 90 seconds.
   3. Using a service wire, connect terminals a4-1 (SVC2) and a4-3 (SGD2), and connect terminals a4-2 (SIG2) and a4-3 (SGD2) of connector C.
      NOTE: Do not forcibly insert a service wire into the terminals of the connector when connecting them.
   4. Measure the resistance of the wire harness side connector.

      Standard resistance 

      RESISTANCE SPECIFIED CONDITION
      
      

      Tester Connection	Specified Condition
      a1-8 (SIG2) - a1-2 (SGD2)	Below 1 Ω
      a1-12 (SVC2) - a1-2 (SGD2)	Below 1 Ω

      NG: REPAIR OR REPLACE FRONT SEAT WIRE RH 

      Fig 2: Checking Front Seat Wire RH (For Open)

      Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

      OK: Go to next step 

5. CHECK FRONT SEAT WIRE RH (FOR SHORT) 
   1. Disconnect the service wire from connector C.
   2. Measure the resistance of the wire harness side connector.

      Standard resistance 

      RESISTANCE SPECIFIED CONDITION
      
      

      Tester Connection	Specified Condition
      a1-8 (SIG2) - a1-2 (SGD2)	1 MΩ or higher
      a1-12 (SVC2) - a1-2 (SGD2)	1 MΩ or higher
      a1-8 (SIG2) - a1-12 (SVC2)	1 MΩ or higher

      NG: REPAIR OR REPLACE FRONT SEAT WIRE RH 

      Fig 3: Checking Front Seat Wire RH (For Short)

      Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

      OK: Go to next step 

6. CHECK FRONT SEAT WIRE RH (TO GROUND) 
   1. Measure the resistance of the wire harness side connector.

      Standard resistance 

      RESISTANCE SPECIFIED CONDITION
      
      

      Tester Connection	Specified Condition
      a1-2 (SGD2) - Body ground	1 MΩ or higher
      a1-8 (SIG2) - Body ground	1 MΩ or higher
      a1-12 (SVC2) - Body ground	1 MΩ or higher

      NG: REPAIR OR REPLACE FRONT SEAT WIRE RH 

      Fig 4: Checking Front Seat Wire RH (To Ground)

      Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

      OK: Go to next step 

7. CHECK FOR DTC 
   1. Connect the connectors to the occupant classification ECU and the front occupant classification sensor RH.
   2. Connect the cable to the negative (-) battery terminal, and wait for at least 2 seconds.
   3. Turn the ignition switch to ON.
   4. Clear the DTCs (see DIAGNOSIS SYSTEM  ).

      HINT:

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

   5. Turn the ignition switch off.
   6. Turn the ignition switch to ON.
   7. Check the DTCs (see DIAGNOSIS SYSTEM  ).

      OK: 

      DTC B1781 is not output. 

      HINT:

      DTCs other than DTC B1781 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 off.
   2. Disconnect the cable from the negative (-) battery terminal, and wait for at least 90 seconds.
   3. Replace the occupant classification ECU (see REMOVAL  ).

      HINT:

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

9. PERFORM ZERO POINT CALIBRATION 
   1. Connect the cable to the negative (-) battery terminal, and wait for at least 2 seconds.
   2. Connect the Techstream to the DLC3.
   3. Turn the ignition switch to ON.
   4. Using the Techstream, perform the zero point calibration (see INITIALIZATION  ).

      OK: 

      "Zero Point Calibration is complete." is displayed. 

      NG: Go to step  12

      OK: Go to next step 

10. PERFORM SENSITIVITY CHECK 
    1. Using the Techstream, perform the 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 FOR DTC 
    1. Connect the cable to the negative (-) battery terminal, and wait for at least 2 seconds.
    2. Turn the ignition switch to ON.
    3. Clear the DTCs (see DIAGNOSIS SYSTEM  ).

       HINT:

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

    4. Turn the ignition switch off.
    5. Turn the ignition switch to ON.
    6. Check the DTCs (see DIAGNOSIS SYSTEM  ).

       OK: 

       DTC B1781 is not output. 

       HINT:

       DTCs other than DTC B1781 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 ASSEMBLY RH 
    1. Turn the ignition switch off.
    2. Disconnect the cable from the negative (-) battery terminal, and wait for at least 90 seconds.
    3. Replace the front seat RH (see FRONT SEAT ASSEMBLY (FOR MANUAL SEAT) ).
13. PERFORM ZERO POINT CALIBRATION 
    1. Connect the cable to the negative (-) battery terminal, and wait for at least 2 seconds.
    2. Connect the Techstream to the DLC3.
    3. Turn the ignition switch to ON.
    4. Using the Techstream, perform the zero point calibration (see INITIALIZATION  ).

       OK: 

       "Zero Point Calibration is complete." is displayed. 

14. PERFORM SENSITIVITY CHECK 
    1. Using the Techstream, perform the sensitivity check (see INITIALIZATION  ).

       Standard value: 

       27 to 33 kg (59.52 to 72.75 lb) 

       NEXT: END