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 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 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 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 LH.

      OK: The connectors are properly connected. 

   NG: CONNECT CONNECTORS 

   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 LH.
   2. Connect the negative (-) terminal cable to the battery.
   3. Turn the ignition switch to the on position.
   4. Measure the voltage.

      Standard voltage 

      TESTER CONNECTION SPECIFIED CONDITION
      
      

      Tester connection	Condition	Specified condition
      U1-1 (SGD1) - Body ground	Ignition switch on	Below 1 V
      U1-7(SIG1) - Body ground	Ignition switch on	Below 1 V
      U1-11(SVC1) - Body ground	Ignition switch on	Below 1 V

   Fig 1: Checking Front Seat Wire RH (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 (FOR OPEN) 
   1. Turn the ignition switch to the lock position.
   2. Disconnect the negative (-) terminal cable from the battery and wait for at least 90 seconds.
   3. Using a service wire, connect U2-1 (SVC1) and U2-3 (SGD1) and connect U2-2 (SIG1) and U2-3 (SGD1) of connector C.
      NOTE: Do not forcibly insert the service wire into the terminals of the connector when connecting.
   4. Measure the resistance.

      Standard resistance 

      TESTER CONNECTION SPECIFIED CONDITION
      
      

      Tester connection	Condition	Specified condition
      U1-7(SIG1)-U1-1 (SGD1)	Always	Below 1 Ω
      U1-11 (SVC1)-U1-1 (SGD1)	Always	Below 1 Ω

   Fig 2: Checking Front Seat Wire RH (For 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 (FOR SHORT) 
   1. Disconnect the service wire from connector C.
   2. Measure the resistance.

      Standard resistance 

      TESTER CONNECTION SPECIFIED CONDITION
      
      

      Tester connection	Condition	Specified condition
      U1-7(SIG1)-U1-1 (SGD1)	Always	1 MΩ or higher
      U1-11(SVC1)-U1-1 (SGD1)	Always	1 MΩ or higher
      U1-7(SIG1)-U1-11 (SVC1)	Always	1 MΩ or higher

   NG: REPAIR OR REPLACE FRONT SEAT WIRE RH 

   Fig 3: Checking Front Seat Wire RH (TO B+)

   Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

   OK: GO TO NEXT STEP 

6. CHECK FRONT SEAT WIRE RH (TO GROUND) 
   1. Measure the resistance.

      Standard resistance 

      TESTER CONNECTION SPECIFIED CONDITION
      
      

      Tester connection	Condition	Specified condition
      U1-1 (SGD1) - Body ground	Always	1 MΩ or higher
      U1-7(SIG1) - Body ground	Always	1 MΩ or higher
      U1-11 (SVC1) - Body ground	Always	1 MΩ or higher

   Fig 4: Checking Front Seat Wire RH (TO B+)
   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 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 and wait for at least 90 seconds.
   3. Replace the occupant classification ECU (See ON-VEHICLE INSPECTION  ).

      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 to the on position.
   4. Using the techstream, perform the 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 the Techstream, perform the sensitivity check (See INITIALIZATION  ).
       1. Confirm that nothing is placed on the passenger seat.
       2. Confirm that the beginning sensor reading is within the standard range.

          Standard range: -3.2 to 3.2 kg (-7 to 7 lb) 

       3. Place a 30 kg (66.14 lb) weight (e.g. a lead mass) onto the front passenger seat.
       4. Confirm that the sensitivity is within the standard range.

          Standard range: 27 to 33 kg (59.52 to 72.75 lb) 

          HINT:

          When performing the sensitivity check, use a solid metal weight (the check result may not be accurate if a liquid weight is used).

       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 ASSEMBLY RH 
    1. Turn the ignition switch to the lock position.
    2. Disconnect the negative (-) terminal cable from the battery and wait for at least 90 seconds.
    3. Replace the front seat assembly RH.

       for Hatchback: (See REMOVAL )

       for Sedan: (See REMOVAL )

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 to the on position.
    4. Using the Techstream, perform the zero point calibration (See INITIALIZATION  ).

       OK: COMPLETED is displayed. 

14. PERFORM SENSITIVITY CHECK 
    1. Using the Techstream, perform the sensitivity check (See INITIALIZATION  ).
       1. Confirm that nothing is placed on the passenger seat.
       2. Confirm that the beginning sensor reading is within the standard range.

          Standard range: -3.2 to 3.2 kg (-7 to 7 lb) 

       3. Place a 30 kg (66.14 lb) weight (e.g. a lead mass) onto the front passenger seat.
       4. Confirm that the sensitivity is within the standard range.

          Standard range: 27 to 33 kg (59.52 to 72.75 lb) 

          HINT:

          When performing the sensitivity check, use a solid metal weight (the check result may not be accurate if a liquid weight is used).