Inspection Procedure

HINT:

• If troubleshooting (wire harness inspection) is difficult to perform, remove the passenger seat installation bolts to see the undersurface 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.
• After performing the zero point calibration, check for DTCs to confirm that the calibration is completed normally. (If it fails, DTC B1797 will be output.)

1. CHECK FOR DTC 
   1. Turn the ignition switch ON.
   2. Clear the DTCs stored in the occupant classification ECU (see DTC CHECK / CLEAR  ).
   3. Clear the DTCs stored in the center airbag sensor (see DTC CHECK / CLEAR  ).
   4. Turn the ignition switch OFF.
   5. Turn the ignition switch ON.
   6. Check for the DTCs (see DTC CHECK / CLEAR  ).

      OK: 

      DTC B1774 and B1775 are not output. 

      HINT:

      Codes other than B1774 and B1775 may be output at this time, but they are not related to this check.

   OK: USE SIMULATION METHOD TO CHECK (See  DIAGNOSIS SYSTEM   ) 

   NG: Go to next step 

2. CHECK CONNECTION OF CONNECTOR 
   1. Turn the ignition switch OFF.
   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 occupant classification sensor.

      OK: 

      Connectors are properly connected. 

   NG: CONNECT CONNECTORS PROPERLY 

   OK: Go to next step 

3. CHECK CONNECTOR 
   1. Disconnect the connectors from the occupant classification ECU and the occupant classification sensor.
   2. Check that the connectors (on the center airbag sensor and occupant classification sensor side) are not damaged.

      OK: 

      Connectors are not deformed or damaged. 

   NG: REPAIR OR REPLACE FRONT SEAT WIRE RH 

   OK: Go to next step 

4. CHECK FRONT SEAT WIRE RH 
   1. Connect the negative (-) terminal cable to the battery.
   2. Turn the ignition switch ON.
   3. Measure the voltage according to the value(s) in the table below.

      Standard voltage 

      TESTER CONNECTION SPECIFIED CONDITION
      
      

      Tester Connection	Switch Condition	Specified Condition
      X5-6 (PS) - Body ground	Ignition switch ON	Below 1 V
      X5-7 (VPS) - Body ground
      X5-15 (GPS) - Body ground

   4. Turn the ignition switch OFF.
   5. Disconnect the negative (-) terminal cable from the battery, and wait for at (east 90 seconds.
   6. Using 2 service wires, connect terminals 1 (GPS) and 3 (VPS), and connect terminals 2 (PS) and 3 (VPS) of connector C.
      Fig 1: Checking Front Seat Wire RH

      Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
      NOTE: Do not forcibly insert the service wires into the terminals of the connector when connecting the wire.
   7. Measure the resistance according to the value(s) in the table below.

      Standard resistance 

      TESTER CONNECTION SPECIFIED CONDITION
      
      

      Tester Connection	Condition	Specified Condition
      X5-6 (PS) - X5-7 (VPS)	Always	Below 1 Ω
      X5-7 (VPS) - X5-15 (GPS)

   8. Disconnect the service wires from connector C.
   9. Measure the resistance according to the value(s) in the table below.

      Standard resistance 

      TESTER CONNECTION SPECIFIED CONDITION
      
      

      Tester Connection	Condition	Specified Condition
      X5-6 (PS) - Body ground	Always	1 MΩ or higher
      X5-7 (VPS) - Body ground
      X5-15 (GPS) - Body ground
      X5-6 (PS) - X5-15 (GPS)
      X5-7 (VPS) - X5-15 (GPS)

   NG: REPAIR OR REPLACE FRONT SEAT WIRE RH 

   OK: Go to next step 

5. CHECK FOR DTC 
   1. Connect the connectors to the occupant classification ECU and the occupant classification sensor.
   2. Connect the negative (-) terminal cable to the battery.
   3. Turn the ignition switch ON.
   4. Clear the DTCs stored in the occupant classification ECU (see DTC CHECK / CLEAR  ).
   5. Clear the DTCs stored in the center airbag sensor (see ON-VEHICLE INSPECTION  ).
   6. Turn the ignition switch OFF.
   7. Turn the ignition switch ON.
   8. Check for the DTCs (see DTC CHECK / CLEAR  ).

      OK: 

      DTCs B1774 and B1775 are not output. 

      HINT:

      Codes other than B1774 and B1775 may be output at this time, but they are not related to this check.

   OK: USE SIMULATION METHOD TO CHECK (See  DIAGNOSIS SYSTEM   ) 

   NG: Go to next step 

6. REPLACE FRONT SEAT CUSHION ASSEMBLY (OCCUPANT CLASSIFICATION SENSOR) 
   1. Turn the ignition switch OFF.
   2. Disconnect the negative (-) terminal cable from the battery, and wait for at least 90 seconds.
   3. Replace the front seat cushion (with occupant classification ECU and occupant classification sensor) (see REMOVAL ).

      HINT:

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

   4. Connect the negative (-) terminal cable to the battery.
   5. Turn the ignition switch ON.
   6. Clear the DTCs stored in the occupant classification ECU (see DTC CHECK / CLEAR  ).
   7. Clear the DTCs stored in the center airbag sensor (see ON-VEHICLE INSPECTION  )
   8. Turn the ignition switch OFF.
   9. Turn the ignition switch ON.
   10. Check for the DTCs (see DTC CHECK / CLEAR  ).

       OK: 

       DTC B1774 and B1775 are not output. 

       HINT:

       Codes other than B1774 and B1775 may be output at this time, but they are not related to this check.

7. PERFORM ZERO POINT CALIBRATION 
   1. Connect the intelligent tester (with CAN VIM) to the DLC3.
   2. Turn the ignition switch ON.
   3. Using the intelligent tester, perform the zero point calibration (see INITIALIZATION  ).
   4. Turn the ignition switch OFF.
   5. Turn the ignition switch ON.
   6. Clear the DTCs stored in the memory (see DTC CHECK / CLEAR  ).

      HINT:

      If DTC is not cleared at this time, past DTC will remain.

8. CHECK FOR DTC 

   HINT:

   Check that the zero point calibration is completed normally. If any of the following conditions is met, DTC B1797 will be output (refer to INITIALIZATION .

   • Zero point calibration is performed when the conditions for the calibration are not satisfied.
   • Zero point calibration has failed.
   1. Turn the ignition switch ON.
   2. Clear the DTCs stored in the occupant classification ECU (see DTC CHECK / CLEAR  ).
   3. Clear the DTCs stored in the center airbag sensor (see DTC CHECK / CLEAR  ).
   4. Turn the ignition switch OFF.
   5. Turn the ignition switch ON.
   6. Check for the DTCs (see DTC CHECK / CLEAR  ).

      OK: 

      DTC B1797 is not output. 

   NG: Go to  DTC B1797  

   OK: Go to next step 

9. PERFORM SENSITIVITY CHECK 
   1. Perform the sensitivity check (see INITIALIZATION  ).

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