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 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 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 B1790 is not output. 

      HINT:

      Codes other than DTC B1790 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.
   3. Check that the connectors are properly connected to the occupant classification ECU and the center airbag sensor assembly.

      OK: The connectors are properly connected. 

   NG: CONNECT CONNECTORS 

   OK : Go to Next Step 

3. CHECK OCCUPANT CLASSIFICATION SYSTEM CIRCUIT (SHORT TO B+) 
   1. Disconnect the connectors from the occupant classification ECU and the center airbag sensor assembly.
   2. Connect the negative (-) terminal cable to the battery.
   3. Turn the ignition switch to the ON position.
   4. Measure the voltage according to the value(s) in the table below.

      Standard voltage 

      OCCUPANT CLASSIFICATION SYSTEM CIRCUIT (SHORT TO B+)
      
      

      Tester connection	Condition	Specified condition
      O4-8 (FSR+) - Body ground	Ignition switch ON	Below 1 V
      O4-4 (FSR-) - Body ground	Ignition switch ON	Below 1 V

      Fig 1: Checking Occupant Classification System Circuit (Short To B+)

      Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

      Result 

      RESULT REFERENCE CHART
      
      

      Result	Proceed to
      OK	A
      NG (with Side and curtain shield airbag)	B
      NG (without Side and curtain shield airbag)	C

   B: REPAIR OR REPLACE FLOOR WIRE 

   C: REPAIR OR REPLACE INSTRUMENT PANEL WIRE NO. 3 

   A: Go to Next Step 

4. CHECK OCCUPANT CLASSIFICATION SYSTEM CIRCUIT (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 A14-12 (FSP+) and A14-13 (FSP-) of connector "B".
      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 

      OCCUPANT CLASSIFICATION SYSTEM CIRCUIT (OPEN)
      
      

      Tester connection	Condition	Specified condition
      O4-8 (FSR+) - O4-4 (FSR-)	Always	Below 1 Ω

      Result 

      RESULT REFERENCE CHART
      
      

      Result	Proceed to
      OK	A
      NG (with Side and curtain shield airbag)	B
      NG (without Side and curtain shield airbag)	C

      Fig 2: Checking Occupant Classification System Circuit (Open)

      Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

   B: REPAIR OR REPLACE FLOOR WIRE 

   C: REPAIR OR REPLACE INSTRUMENT PANEL WIRE NO. 3 

   A: Go to Next Step 

5. CHECK OCCUPANT CLASSIFICATION SYSTEM CIRCUIT (SHORT) 
   1. Disconnect the service wire from connector "B".
   2. Measure the resistance according to the value(s) in the table below.

      Standard resistance 

      OCCUPANT CLASSIFICATION SYSTEM CIRCUIT (SHORT)
      
      

      Tester connection	Condition	Specified condition
      O4-8 (FSR+) - O4-4 (FSR-)	Always	1 MΩ or higher

      Result 

      RESULT REFERENCE CHART
      
      

      Result	Proceed to
      OK	A
      NG (with Side and curtain shield airbag)	B
      NG (without Side and curtain shield airbag)	C

      Fig 3: Checking Occupant Classification System Circuit (Short)

      Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

   B: REPAIR OR REPLACE FLOOR WIRE 

   C: REPAIR OR REPLACE INSTRUMENT PANEL WIRE NO. 3 

   A: Go to Next Step 

6. CHECK OCCUPANT CLASSIFICATION SYSTEM CIRCUIT (SHORT TO GROUND) 
   1. Measure the resistance according to the value(s) in the table below.

      Standard resistance 

      OCCUPANT CLASSIFICATION SYSTEM CIRCUIT (SHORT TO GROUND)
      
      

      Tester connection	Condition	Specified condition
      O4-8 (FSR+) - Body ground	Always	1 MΩ or higher
      O4-4 (FSR-) - Body ground	Always	1 MΩ or higher

      Result 

      RESULT REFERENCE CHART
      
      

      Result	Proceed to
      OK	A
      NG (with Side and curtain shield airbag)	B
      NG (without Side and curtain shield airbag)	C

      Fig 4: Checking Occupant Classification System Circuit (Short To Ground)

      Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

   B: REPAIR OR REPLACE FLOOR WIRE 

   C: REPAIR OR REPLACE INSTRUMENT PANEL WIRE NO. 3 

   A: Go to Next Step 

7. CHECK DTC 
   1. Connect the connectors to the occupant classification ECU and the center airbag sensor assembly.
   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 B1790 is not output. 

      HINT:

      Codes other than DTC B1790 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.
   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 intelligent tester to the DLC3.
   3. Turn the ignition switch to the ON position.
   4. Using the intelligent tester, perform "Zero point calibration" (See INITIALIZATION  ).

      OK: "COMPLETED" is displayed. 

10. PERFORM SENSITIVITY CHECK 
    1. Using the intelligent tester, perform "Sensitivity check" (See INITIALIZATION  ).

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

11. 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 B1790 is not output. 

       HINT:

       Codes other than DTC B1790 may be output at this time, but they are not related to this check.

    NG: REPLACE CENTER AIRBAG SENSOR ASSEMBLY 

    OK : END