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 engine 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 (see DTC CHECK / CLEAR  ).
   4. Turn the engine switch off.
   5. Turn the engine switch on (IG).
   6. Check for the DTCs (see DTC CHECK/CLEAR  ).

      OK: DTCs B1774 and B1775 are not output. 

      HINT:

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

   NG: Go to step 2 

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

2. CHECK CONNECTION OF CONNECTOR 
   1. Turn the engine 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 detection 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 detection sensor.
   2. Check that the connectors (on the center airbag sensor and occupant detection sensor side) are not damaged.

      OK: Connectors are not deformed or damaged. 

   NG: 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.
   Fig 1: Identifying Front Seat Wire RH
   Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
   2. Turn the engine switch on (IG).
   3. Measure the voltage according to the value(s) in the table below.

      Standard voltage 

      TESTER CONNECTION SPECIFIED CONDITION CHART
      
      

      Tester Connection	Switch Condition	Specified condition
      e10-6(PS)-Body ground	Engine switch on (IG)	Below 1 V
      e10-7 (VPS)-Body ground
      e10-15 (GPS)-Body ground

   4. Turn the engine switch off.
   5. Disconnect the negative (-) terminal cable from the battery, and wait for at least 90 seconds.
   6. Using 2 service wires, connect terminals 1 (VPS) and 3 (GPS), and connect terminals 2 (PS) and 3 (GPS) of connector C.
      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 CHART
      
      

      Tester Connection	Condition	Specified condition
      e10-6(PS)-e10-7(VPS)	Always	Below 1 Ω
      e10-7(VPS)-e10-15 (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 CHART
      
      

      Tester Connection	Condition	Specified condition
      e10-6(PS)-Body ground	Always	1 MΩ or higher
      e10-7 (VPS) -Body ground
      e10-15(GPS) -Body ground
      e10-6(PS)-e10-15 (GPS)
      e10-7(VPS)-e10-15 (GPS)

   NG: 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 detection sensor.
   2. Connect the negative (-) terminal cable to the battery.
   3. Turn the engine 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 (see DTC CHECK / CLEAR  ).
   6. Turn the engine switch off.
   7. Turn the engine switch on (IG).
   8. Check for the DTCs (see DTC CHECK/CLEAR  ).

      OK: DTCs B1774 and B1775 are not output. 

      HINT:

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

   NG: Go to step 6 

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

6. REPLACE FRONT SEAT SET (OCCUPANT DETECTION SENSOR) 
   1. Turn the engine switch off.
   2. Disconnect the negative (-) terminal cable from the battery, and wait for at least 90 seconds.
   3. Replace the front seat set (with occupant classification ECU and occupant detection sensor) (see DISASSEMBLY ).

      HINT:

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

   4. Connect the negative (-) terminal cable to the battery.
   5. Turn the engine switch on (IG).
   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 CHECK MODE PROCEDURE  )
   8. Turn the engine switch off.
   9. Turn the engine switch on (IG).
   10. Check for the DTCs (see DTC CHECK/CLEAR  ).

       OK: DTCs B1774 and B1775 are not output. 

       HINT:

       Codes other than DTCs 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 or Techstream to the DLC3.
   2. Turn the engine switch on (IG).
   3. Using the intelligent tester or Techstream, perform zero point calibration (see INITIALIZATION  ).
   4. Turn the engine switch off.
   5. Turn the engine switch on (IG).
   6. Clear the DTCs stored in the memory (see DTC CHECK/CLEAR  ).

      HINT:

      If DTCs are not cleared at this time, past DTCs will remain.

8. CHECK FOR DTC 

   HINT:

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

   • Zero point calibration is performed when the conditions for the calibration are not satisfied.
   • Zero point calibration has failed.
   1. Turn the engine 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 (see DTC CHECK / CLEAR  ).
   4. Turn the engine switch off.
   5. Turn the engine switch on (IG).
   6. Check for the DTCs (see DTC CHECK/CLEAR  ).

      OK: DTC B1797 is not output. 

   NG: Go to  DTC B1797   (See ) 

   OK: GO TO NEXT STEP 

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

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