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 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 on (IG).
   2. Clear the DTCs stored in the occupant classification ECU (See DTC CHECK / CLEAR  ).
   3. Clear the DTCs stored in the center airbag sensor assembly (See DTC CHECK/CLEAR  ).
   4. Turn the ignition switch off.
   5. Turn the ignition switch on (IG).
   6. Check the DTCs (See DTC CHECK / CLEAR  ).

      OK: 

      DTC B1781 is not output. 

      HINT:

      Codes 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 

2. CHECK CONNECTION OF CONNECTORS 
   1. Turn the ignition switch off.
   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 RH.

      OK: 

      The connectors are connected. 

   NG: CONNECT CONNECTORS, THEN GO TO STEP  1

   OK: Go to next step 

3. CHECK FRONT SEAT WIRE RH (SHORT TO B+) 
   1. Disconnect the connectors from the occupant classification ECU and the front occupant classification sensor RH.
   2. Connect the negative (-) terminal cable to the battery.
   3. Turn the ignition switch on (IG).
   4. Measure the voltage according to the value(s) in the table below.

      Standard voltage 

      TESTER CONNECTION SPECIFIED CONDITION CHART
      
      

      Tester connection	Condition	Specified condition
      O2-2 (SGD2) - Body ground	Ignition switch on (IG)	Below 1 V
      O2-8 (SIG2) - Body ground	Ignition switch on (IG)	Below 1 V
      O2-12 (SVC2) - Body ground	Ignition switch on (IG)	Below 1 V

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

      Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

   NG: REPAIR OR REPLACE FRONT SEAT WIRE RH 

   OK: Go to next step 

4. CHECK FRONT SEAT WIRE RH (OPEN) 
   1. Turn the ignition switch off.
   2. Disconnect the negative (-) terminal cable from the battery.
   3. Using a service wire, connect O7-1 (SVC2) and O7-3 (SGD2), and connect O7-2 (SIG2) and O7-3 (SGD2) 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 CHART
      
      

      Tester connection	Condition	Specified condition
      O2-8 (SIG2) - O2-2 (SGD2)	Always	Below 1 Ω
      O2-12 (SVC2) - O2-2 (SGD2)	Always	Below 1 Ω

      Fig 2: Checking Front Seat Wire RH (Open)

      Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

   NG: REPAIR OR REPLACE FRONT SEAT WIRE RH 

   OK: Go to next step 

5. CHECK FRONT SEAT WIRE RH (SHORT) 
   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 CHART
      
      

      Tester connection	Condition	Specified condition
      O2-8 (SIG2) - O2-2 (SGD2)	Always	1 MΩ or Higher
      O2-12 (SVC2) - O2-2 (SGD2)	Always	1 MΩ or Higher
      O2-8 (SIG2) - O2-12 (SVC2)	Always	1 MΩ or Higher

      Fig 3: Checking Front Seat Wire RH (Short)

      Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

   NG: REPAIR OR REPLACE FRONT SEAT WIRE RH 

   OK: Go to next step 

6. CHECK FRONT SEAT WIRE RH (SHORT TO GROUND) 
   1. Measure the resistance according to the value(s) in the table below.

      Standard resistance 

      TESTER CONNECTION SPECIFIED CONDITION CHART
      
      

      Tester connection	Condition	Specified condition
      O2-2 (SGD2) - Body ground	Always	1 MΩ or Higher
      O2-8 (SIG2) - Body ground	Always	1 MΩ or Higher
      O2-12 (SVC2) - Body ground	Always	1 MΩ or Higher

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

      Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

   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 RH.
   2. Connect the negative (-) terminal cable to the battery.
   3. Turn the ignition switch on (IG).
   4. Clear the DTCs stored in the occupant classification ECU (See DTC CHECK / CLEAR  ).
   5. Clear the DTCs stored in the center airbag sensor assembly (See DTC CHECK/CLEAR  ).
   6. Turn the ignition switch off.
   7. Turn the ignition switch on (IG).
   8. Check the DTCs (See DTC CHECK / CLEAR  ).

      OK: 

      DTC B1781 is not output. 

      HINT:

      Codes 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 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.

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

      OK: 

      The "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 "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. Turn the ignition switch on (IG).
    2. Clear the DTCs stored in the occupant classification ECU (See DTC CHECK / CLEAR  ).
    3. Clear the DTCs stored in the center airbag sensor assembly (See DTC CHECK/CLEAR  ).
    4. Turn the ignition switch off.
    5. Turn the ignition switch on (IG).
    6. Check the DTCs (See DTC CHECK / CLEAR  ).

       OK: 

       DTC B1781 is not output. 

       HINT:

       Codes 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 negative (-) terminal cable from the battery.
    3. Replace the front seat assembly RH (See REMOVAL for power seat or REMOVAL for manual seat).
13. PERFORM ZERO POINT CALIBRATION 
    1. Connect the negative (-) terminal cable to the battery.
    2. Connect the Techstream to the DLC3.
    3. Turn the ignition switch on (IG).
    4. Using the Techstream, perform "Zero point calibration" (See INITIALIZATION  ).

       OK: 

       The "Zero Point Calibration is complete." is displayed. 

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

       Standard value: 

       27 to 33 kg (59.52 to 72.75 lb) 

    NEXT : END