Inspection Procedure

WARNING: This page is about a different car, the 2008 Toyota Tundra. However, it is still accessible from the selected car via links, so may be relevant.

NOTE: After the ignition switch is turned OFF, the navigation system requires approximately 90 seconds to record various types of memory and settings. As a result, after turning the ignition switch OFF, wait 90 seconds or more before disconnecting the cable from the negative (-) battery terminal.

HINT:

If troubleshooting (wire harness inspection) is difficult to perform, remove the front seat RH 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 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, and wait for at least 60 seconds.
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.
  - Use the Techstream to clear the DTCs of the occupant classification ECU, otherwise the DTCs cannot be cleared.
3. Turn the ignition switch OFF.
4. Turn the ignition switch ON, and wait for at least 60 seconds.
5. Using the Techstream, check for DTCs of the occupant classification ECU (see DTC CHECK/CLEAR ).
  OK: DTC B1781 is not output.
  
  HINT:
  
  DTCs other than DTC B1781 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 )
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 front occupant detection sensor RH.
  OK: Connectors are properly connected.
NG: CONNECT CONNECTOR

OK: Go to next step
CHECK CONNECTOR
1. Check that the connectors (on the occupant classification ECU side and front occupant detection sensor RH side) are not damaged (see ELECTRONIC CIRCUIT INSPECTION PROCEDURE ).
  OK: Connectors are not deformed or damaged.
NG: REPLACE FRONT SEAT WIRE RH

OK: Go to next step

CHECK FRONT SEAT WIRE RH

Disconnect the connectors from the occupant classification ECU and the front occupant detection sensor RH.
Connect the negative (-) terminal cable to the battery, and wait for at least 2 seconds.
Turn the ignition switch ON, and wait for at least 60 seconds.

Measure the voltage according to the value(s) in the table below.

Standard voltage

TESTER CONNECTION SPECIFIED CONDITION TABLE

Tester Connection	Switch Condition	Specified Condition
Y1-2 (SGD2) - Body ground	Ignition switch ON	Below 1 V
Y1-8 (SIG2) - Body ground
Y1-12 (SVC2) - Body ground

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

Measure the resistance according to the value(s) in the table below.

Fig 1: Identifying Front Seat Wire RH

Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

Standard resistance

TESTER CONNECTION SPECIFIED CONDITION TABLE

Tester Connection	Condition	Specified Condition
Y1-8 (SIG2) - Y1-2 (SGD2)	Always	Below 1 Ω
Y1-12 (SVC2) - Y1-2 (SGD2)	Always	Below 1 Ω

Disconnect the service wires from connector C.

Measure the resistance according to the value(s) in the table below.

Standard resistance

TESTER CONNECTION SPECIFIED CONDITION TABLE

Tester Connection	Condition	Specified Condition
Y1-8 (SIG2) - Y1-2 (SGD2)	Always	1 MΩ or higher
Y1-12 (SVC2) - Y1-2 (SGD2)
Y1-8 (SIG2) - Y1-12 (SVC2)
Y1-2 (SGD2) - Body ground
Y1-8 (SIG2) - Body ground
Y1-12 (SVC2) - Body ground

NG: REPLACE FRONT SEAT WIRE RH

OK: Go to next step

CHECK FOR DTC
1. Connect the connectors to the occupant classification ECU and the front occupant detection sensor RH.
2. Connect the negative (-) terminal cable to the battery, and wait for at least 2 seconds.
3. Turn the ignition switch ON, and wait for at least 60 seconds.
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.
  - Use the Techstream to clear the DTCs of the occupant classification ECU, otherwise the DTCs cannot be cleared.
5. Turn the ignition switch OFF.
6. Turn the ignition switch ON, and wait for at least 60 seconds.
7. Using the Techstream, check for DTCs of the occupant classification ECU (see DTC CHECK/CLEAR ).
  OK: DTC B1781 is not output.
  
  HINT:
  
  DTCs other than DTC B1781 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 )
REPLACE OCCUPANT CLASSIFICATION ECU
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 occupant classification ECU.
  - for Manual Seat (see FRONT SEAT ASSEMBLY (FOR FOLD DOWN SEAT TYPE) )
  - for Power Seat (see FRONT SEAT ASSEMBLY (FOR POWER SEAT) )
  HINT:
  
  Perform the inspection using parts from a normal vehicle when possible.
PERFORM ZERO POINT CALIBRATION
1. Connect the negative (-) terminal cable to the battery, and wait for at least 2 seconds.
2. Connect the Techstream to the DLC3.
3. Turn the ignition switch ON, and wait for at least 60 seconds.
4. Using the Techstream, perform the zero point calibration (see INITIALIZATION ).
NG: Go to step 10

OK: Go to next step
PERFORM SENSITIVITY CHECK
1. Using the Techstream, perform the sensitivity check (see INITIALIZATION ).
  Standard range:
  
  27 to 33 kg (59.5 to 72.8 lb)
NG: Go to step 10

OK: Go to next step
CHECK FOR DTC
1. Turn the ignition switch ON, and wait for at least 60 seconds.
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.
  - Use the Techstream to clear the DTCs of the occupant classification ECU, otherwise the DTCs cannot be cleared.
3. Turn the ignition switch OFF.
4. Turn the ignition switch ON, and wait for at least 60 seconds.
5. Using the Techstream, check for DTCs of the occupant classification ECU (see DTC CHECK/CLEAR ).
  OK: DTC B1781 is not output.
  
  HINT:
  
  DTCs other than DTC B1781 may be output at this time, but they are not related to this check.
NG: Go to step 10

OK: END
REPLACE FRONT SEAT FRAME WITH ADJUSTER ASSEMBLY RH
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 frame with adjuster RH (see FRONT POWER SEAT MOTOR ASSEMBLY (FOR POWER SEAT) ).
  HINT:
  
  Perform the inspection using parts from a normal vehicle when possible.
PERFORM ZERO POINT CALIBRATION
1. Connect the negative (-) terminal cable to the battery, and wait for at least 2 seconds.
2. Connect the Techstream to the DLC3.
3. Turn the ignition switch ON, and wait for at least 60 seconds.
4. Using the Techstream, perform the zero point calibration (see INITIALIZATION ).
PERFORM SENSITIVITY CHECK
1. Using the Techstream, perform the sensitivity check (see INITIALIZATION ).
  Standard range:
  
  27 to 33 kg (59.5 to 72.8 lb)
NEXT: END