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.

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 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
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 RH.
  OK: The connectors are properly connected.
NG: CONNECT CONNECTORS

OK: Go TO NEXT STEP

CHECK NO.1 SEAT WIRE (TO B+)

Disconnect the connectors from the occupant classification ECU and the front occupant classification sensor RH.

Fig 1: Identifying Front Occupant Classification Sensor RH & No. 1 Seat Wire (To B+)
Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
Connect the negative (-) terminal cable to the battery.
Turn the ignition switch to the on position.

Measure the voltage.

Standard voltage

TESTER CONNECTION SPECIFIED CONDITION TABLE

Tester connection	Condition	Specified condition
Q5-2 (SGD2) - Body ground	Ignition switch on	Below 1 V
Q5-8 (SIG2) - Body ground	Ignition switch on	Below 1 V
Q5-12 (SVC2) - Body ground	Ignition switch on	Below 1 V

NG: REPAIR OR REPLACE NO.1 SEAT WIRE

OK: Go TO NEXT STEP

CHECK NO. 1 SEAT WIRE (FOR OPEN)

Fig 2: Identifying Front Occupant Classification Sensor RH & No. 1 Seat Wire (For Open)

Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

Turn the ignition switch to the lock position.
Disconnect the negative (-) terminal cable from the battery, and wait for at least 90 seconds.
Using a service wire, connect Q7-1 (SVC2) and Q7-3 (SGD2), and connect Q7-2 (SIG2) and Q7-3 (SGD2) of connector C.
NOTE: Do not forcibly insert a service wire into the terminals of the connector when connecting.

Measure the resistance.

Standard resistance

TESTER CONNECTION SPECIFIED CONDITION TABLE

Tester connection	Condition	Specified condition
Q5-8 (SIG2) - Q5-2 (SGD2)	Always	Below 1 Ω
Q5-12 (SVC2) - Q5-2 (SGD2)	Always	Below 1 Ω

NG: REPAIR OR REPLACE NO.1 SEAT WIRE

OK: Go TO NEXT STEP

CHECK NO.1 SEAT WIRE (FOR SHORT)

Fig 3: Identifying Front Occupant Classification Sensor RH & No. 1 Seat Wire (For Short)

Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

Disconnect the service wire from connector C.

Measure the resistance.

Standard resistance

TESTER CONNECTION SPECIFIED CONDITION TABLE

Tester connection	Condition	Specified condition
Q5-8 (SIG2) - Q5-2 (SGD2)	Always	1 MΩ or higher
Q5-12 (SVC2) - Q5-2 (SGD2)	Always	1 MΩ or higher
Q5-8 (SIG2) - Q5-12 (SVC2)	Always	1 MΩ or higher

NG: REPAIR OR REPLACE NO.1 SEAT WIRE

OK: Go TO NEXT STEP

CHECK NO.1 SEAT WIRE (TO GROUND)

Fig 4: Identifying Front Occupant Classification Sensor RH & No. 1 Seat Wire (To Ground)

Measure the resistance.

Standard resistance

TESTER CONNECTION SPECIFIED CONDITION TABLE

Tester connection	Condition	Specified condition
Q5-2 (SGD2) - Body ground	Always	1 MΩ or higher
Q5-8 (SIG2) - Body ground	Always	1 MΩ or higher
Q5-12 (SVC2) - Body ground	Always	1 MΩ or higher

NG: REPAIR OR REPLACE NO.1 SEAT WIRE

OK: Go TO NEXT STEP

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 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 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
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 REMOVAL ).
  HINT:
  
  Perform the inspection using parts from a normal vehicle if possible.
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 the zero point calibration (See INITIALIZATION ).
  OK: COMPLETED is displayed.
NG: Go to step 12

OK: Go TO NEXT STEP
PERFORM SENSITIVITY CHECK
1. Using the intelligent tester, 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
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 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
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 (See REMOVAL ).
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 the zero point calibration (See INITIALIZATION ).
  OK: COMPLETED is displayed.
PERFORM SENSITIVITY CHECK
1. Using the intelligent tester, 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).
NEXT: END