Inspection Procedure

WARNING: This page is about a different car, the 2007 Toyota Land Cruiser. However, it is still accessible from the selected car via links, so may be relevant.

HINT:

If troubleshooting (wire harness inspection) is difficult to perform, remove the front passenger seat installation bolts to see the undersurface of the seat cushion.
In the above case, hold the seat so that it does not tip over. Holding the seat up for a long period of time may cause problems, such as seat rail deformation. Hold the seat up only for as long as necessary.

CHECK FOR DTC
1. Turn the ignition switch ON.
2. Clear any 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.
3. Turn the ignition switch OFF.
4. Turn the ignition switch ON.
5. Check the DTCs (see DTC CHECK/CLEAR ).
  OK: DTC B1790 is not output.
  
  HINT:
  
  DTCs other than 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
CHECK CONNECTOR
1. Turn the ignition switch OFF.
2. Disconnect the cable from the negative (-) battery terminal, and wait for at least 90 seconds.
3. Check that the connectors are properly connected to the occupant classification ECU and the center airbag sensor.
  OK: The connectors are properly connected.
4. Disconnect the connectors from the center airbag sensor and occupant classification ECU.
5. Check that the terminals of the connectors are not damaged.
  OK: The terminals are not deformed or damaged.
  
  HINT:
  
  If the connectors are not connected securely, reconnect the connectors and proceed to the next inspection.
NG: REPAIR OR REPLACE HARNESS OR CONNECTOR

OK: GO TO NEXT STEP

CHECK CENTER AIRBAG SENSOR COMMUNICATION CIRCUIT (TO B+)

Disconnect the connectors from the occupant classification ECU and center airbag sensor.
Connect the cable to the negative (-) battery terminal.
Turn the ignition switch ON.

Measure the voltage of the wire harness side connector.

Standard voltage

CENTER AIRBAG SENSOR COMMUNICATION CIRCUIT (TO B+)

Tester Connection	Specified Condition
O6-11 (FSR+) - Body ground	Below 1 V
O6-12 (FSR-) - Body ground	Below 1 V

Fig 1: Checking Center Airbag Sensor Communication Circuit (To B+)

Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

NG: Go to step 12

OK: GO TO NEXT STEP

CHECK CENTER AIRBAG SENSOR COMMUNICATION CIRCUIT (FOR OPEN)

Turn the ignition switch OFF.
Disconnect the cable from the negative (-) battery terminal, and wait for at least 90 seconds.
Using a service wire, connect terminals C27-12 (FSR+) and C27-13 (FSR-) of connector B.
NOTE: Do not forcibly insert the service wire into the terminals of the connector when connecting.

Measure the resistance of the wire harness side connector.

Standard resistance

CENTER AIRBAG SENSOR COMMUNICATION CIRCUIT (FOR OPEN)

Tester Connection	Specified Condition
O6-11 (FSR+) - O6-12 (FSR-)	Below 1 Ω

Fig 2: Checking Center Airbag Sensor Communication Circuit (For Open)

Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

NG: Go to step 13

OK: GO TO NEXT STEP

CHECK CENTER AIRBAG SENSOR COMMUNICATION CIRCUIT (TO GROUND)

Disconnect the service wire from connector B.

Measure the resistance of the wire harness side connector.

Standard resistance

CENTER AIRBAG SENSOR COMMUNICATION CIRCUIT (TO GROUND)

Tester Connection	Specified Condition
O6-11 (FSR+) - Body ground	1 MΩ or higher
O6-12 (FSR-) - Body ground	1 MΩ or higher

Fig 3: Checking Center Airbag Sensor Communication Circuit (To Ground)

Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

NG: Go to step 14

OK: GO TO NEXT STEP

CHECK CENTER AIRBAG SENSOR COMMUNICATION CIRCUIT (FOR SHORT)

Measure the resistance of the wire harness connector.

Standard resistance

CENTER AIRBAG SENSOR COMMUNICATION CIRCUIT (FOR SHORT)

Tester Connection	Specified Condition
O6-11 (FSR+) - O6-12 (FSR-)	1 MΩ or higher

Fig 4: Checking Center Airbag Sensor Communication Circuit (For Short)

Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

NG: Go to step 15

OK: GO TO NEXT STEP.

RECHECK FOR DTC
1. Connect the connectors to the occupant classification ECU and the center airbag sensor.
2. Connect the cable to the negative (-) battery terminal.
3. Turn the ignition switch ON.
4. Clear any 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.
5. Turn the ignition switch OFF.
6. Turn the ignition switch ON.
7. Check the DTCs (see DTC CHECK/CLEAR ).
  OK: DTC B1790 is not output.
  
  HINT:
  
  DTCs other than B1790 may be output at this time, but they are not related to this check.
NG: USE SIMULATION METHOD TO CHECK

NG: GO TO NEXT STEP
REPLACE OCCUPANT CLASSIFICATION ECU
1. Connect the intelligent tester (with CAN VIM) to the DLC3.
2. Turn the ignition switch ON.
3. Store the occupant classification ECU data into the intelligent tester (see DIAGNOSTIC TROUBLE CODE TABLE ).
  HINT:
  
  If the ECU data cannot be stored in the intelligent tester, replace the front seat cushion (with occupant classification ECU and occupant classification sensor).
4. Turn the ignition switch OFF.
5. Disconnect the cable from the negative (-) battery terminal, and wait for at least 90 seconds.
6. Replace the occupant classification ECU (see REMOVAL ).
7. Connect the cable to the negative (-) battery terminal.
8. Turn the ignition switch ON.
9. Load the data from the previous ECU stored in the tester into the newly installed ECU (see REGISTRATION ).
10. Turn the ignition switch OFF.
11. Turn the ignition switch ON.
12. Clear the DTCs stored in the memory (see DTC CHECK/CLEAR ).
  HINT:
  
  If DTCs are not cleared at this time, past DTCs will remain.
CHECK FOR DTC
1. Turn the ignition switch ON.
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.
3. Turn the ignition switch OFF.
4. Turn the ignition switch ON.
5. Check the DTCs (see DTC CHECK/CLEAR ).
  OK: DTC B1790 is not output.
  
  HINT:
  
  DTCs other than B1790 may be output at this time, but they are not related to this check.
OK: Go to step 11

NG: GO TO NEXT STEP
REPLACE CENTER AIRBAG SENSOR
1. Turn the ignition switch OFF.
2. Disconnect the cable from the negative (-) battery terminal, and wait for at least 90 seconds.
3. Replace the center airbag sensor (see REMOVAL ).
PERFORM SENSITIVITY CHECK
1. Perform the sensitivity check (see INITIALIZATION ).
END

CHECK NO. 1 SEAT WIRE (TO B+)

Turn the ignition switch OFF.
Disconnect the cable from the negative (-) battery terminal, and wait for at least 90 seconds.
Disconnect the No. 1 seat wire connector from the floor wire.
Connect the cable to the negative (-) battery terminal and wait for at least 2 seconds.
Turn the ignition switch ON.

Measure the voltage of the wire harness side connector.

Standard voltage

NO. 1 SEAT WIRE (TO B+)

Tester Connection	Specified Condition
BO2-1 (FSR+) - Body ground	Below 1 V
BO2-2 (FSR-) - Body ground	Below 1 V

Fig 5: Checking No. 1 Seat Wire (To B+)

Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

NG: REPAIR OR REPLACE NO. 1 SEAT WIRE

OK: REPAIR OR REPLACE FLOOR WIRE

CHECK NO. 1 SEAT WIRE (FOR OPEN)

Disconnect the No. 1 seat wire connector from the floor wire.
HINT:

The service wire has already been inserted into connector D.

Measure the resistance of the wire harness side connector.

Standard resistance

NO. 1 SEAT WIRE (FOR OPEN)

Tester Connection	Specified Condition
O6-11 (FSR+) - O6-12 (FSR-)	Below 1 Ω

Fig 6: Checking No. 1 Seat Wire (For Open)

NG: REPAIR OR REPLACE NO. 1 SEAT WIRE

OK: REPAIR OR REPLACE FLOOR WIRE

CHECK NO. 1 SEAT WIRE (TO GROUND)

Disconnect the No. 1 seat wire connector from the floor wire.

Measure the resistance of the wire harness side connector.

Standard resistance

NO. 1 SEAT WIRE (TO GROUND)

Tester Connection	Specified Condition
BO2-1 (FSR+) - Body ground	1 MΩ or higher
BO2-2 (FSR-) - Body ground	1 MΩ or higher

Fig 7: Checking No. 1 Seat Wire (To Ground)

NG: REPAIR OR REPLACE NO. 1 SEAT WIRE

OK: REPAIR OR REPLACE FLOOR WIRE

CHECK NO. 1 SEAT WIRE (FOR SHORT)

Disconnect the No. 1 seat wire connector from the floor wire.

Measure the resistance of the wire harness side connector.

Standard resistance

NO. 1 SEAT WIRE (FOR SHORT)

Tester Connection	Specified Condition
BO2-1 (FSR+) - BO2-2 (FSR-)	1 MΩ or higher

Fig 8: Checking No. 1 Seat Wire (For Short)

NG: REPAIR OR REPLACE NO. 1 SEAT WIRE

OK: REPAIR OR REPLACE FLOOR WIRE