Inspection Procedure

WARNING: This page is about a different car, the 2007 Lexus SC 430. 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 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.

CHECK FOR DTC
1. Turn the ignition switch ON.
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 ON-VEHICLE INSPECTION ).
4. Turn the ignition switch OFF.
5. Turn the ignition switch ON.
6. Check for the DTCs (see DTC CHECK / CLEAR ).
  OK:
  
  DTC B1771 is not output.
  
  HINT:
  
  Codes other than B1771 may be output at this time, but they are not related to this check.
OK: USE SIMULATION METHOD TO CHECK (See DIAGNOSIS SYSTEM )

NG: Go to next step
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 seat inner belt RH.
  OK:
  
  Connectors are properly connected.
NG: CONNECT CONNECTORS PROPERLY

OK: Go to next step
CHECK CONNECTOR
1. Disconnect the connectors from the occupant classification ECU and front seat inner belt RH.
2. Check that the connectors (on the center airbag sensor side and front seat inner belt RH) are not damaged.
  OK:
  
  Connectors 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 FRONT SEAT WIRE RH

OK: Go to next step

CHECK FRONT SEAT WIRE RH

Connect the negative (-) terminal cable to the battery.
Turn the ignition switch ON.

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

Standard voltage

TESTER CONNECTION SPECIFIED CONDITION

Tester connection	Switch Condition	Specified condition
X5-13 (BSW) - Body ground	Ignition switch ON	Below 1 V
X5-14 (BGND) - Body ground	Ignition switch ON	Below 1 V

Turn the ignition switch OFF.
Disconnect the negative (-) terminal cable from the battery, and wait for at least 90 seconds.
Using a service wire, connect terminals 3 and 7 of connector C.
NOTE: Do not forcibly insert the service wire into the terminals of the connector when connecting the wire.

Fig 1: Checking Front Seat Wire RH
Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

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

Standard resistance

TESTER CONNECTION SPECIFIED CONDITION

Tester connection	Condition	Specified condition
X5-13 (BSW) - X5-14 (BGND)	Always	Below 1 Ω

Disconnect the service wire from connector C.

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

Standard resistance

TESTER CONNECTION SPECIFIED CONDITION

Tester connection	Condition	Specified condition
X5-13 (BSW) - Body ground	Always	1 MΩ or higher
XS-14 (BGND) - Body ground
X5-13 (BSW)-X5-14 (BGND)

NG: REPAIR OR 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 seat inner belt assembly RH.
2. Connect the negative (-) terminal cable to the battery.
3. Turn the ignition switch ON.
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 ON-VEHICLE INSPECTION )
6. Turn the ignition switch OFF.
7. Turn the ignition switch ON.
8. Check for the DTCs (see DTC CHECK / CLEAR ).
  OK:
  
  DTC B1771 is not output.
  
  HINT:
  
  Codes other than B1771 may be output at this time, but they are not related to this check.
OK: USE SIMULATION METHOD TO CHECK (See DIAGNOSIS SYSTEM )

NG: Go to next step
REPLACE FRONT SEAT INNER BELT ASSEMBLY RH (PASSENGER SIDE BUCKLE SWITCH)
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 inner belt RH (see REMOVAL ).
  HINT:
  
  (d) Perform the inspection using parts from a normal vehicle if possible.
4. Connect the negative (-) terminal cable to the battery.
5. Turn the ignition switch ON.
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 DTC CHECK / CLEAR )
8. Turn the ignition switch OFF.
9. Turn the ignition switch ON.
10. Check for the DTCs (see DTC CHECK / CLEAR ).
  OK:
  
  DTC B1771 is not output.
  
  HINT:
  
  Codes other than B1771 may be output at this time, but they are not related to this check.
OK: END

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. Using the intelligent tester, save the ECU data from the ECU which has been installed on the vehicle (see REGISTRATION ).
4. Turn the ignition switch OFF.
5. Disconnect the negative (-) terminal cable from the battery, and wait for at least 90 seconds.
6. Replace the occupant classification ECU (see REMOVAL ).
7. Connect the negative (-) terminal cable to the battery.
8. Turn the ignition switch ON.
9. Using the intelligent tester, load the previous ECU data stored into the new 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 DTC is not cleared at this time, past DTC will remain.
PERFORM SENSITIVITY CHECK
1. Perform the sensitivity check (see INITIALIZATION ).
NEXT: END