Inspection Procedure

WARNING: This page is about a different car, the 2007 Lexus ES 350. 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 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.
After performing the zero point calibration, check for DTCs to confirm that the calibration is completed normally. (If it fails, DTC B1797 will be output.)

CHECK DTC
1. Turn the engine switch on (IG).
2. Clear the DTCs stored in the occupant classification ECU (See DTC CHECK / CLEAR ).
3. Clear the DTCs stored in the center airbag sensor assembly (See DTC CHECK/CLEAR ).
4. Turn the engine switch off.
5. Turn the engine switch on (IG).
6. Check the DTCs (See DTC CHECK / CLEAR ).
  OK: DTC B1774 and B1775 are not output.
  
  HINT:
  
  Codes other than B1774 and B1775 may be output at this time, but they are not related to this check.
OK: USE SIMULATION METHOD TO CHECK (See TERMINALS OF ECU )

NG: Go to Next Step
CHECK CONNECTION OF CONNECTORS
1. Turn the engine 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 occupant classification sensor.
  OK: The connectors are properly connected.
NG: CONNECT CONNECTORS PROPERLY, THEN GO TO STEP 1

OK: Go to Next Step
CHECK CONNECTORS
1. Disconnect the connectors from the occupant classification ECU and the occupant classification sensor.
2. Check that the connectors (on the center airbag sensor assembly and occupant classification sensor side) are not damaged.
  OK: The connectors are not deformed or damaged.
NG: REPAIR OR REPLACE FRONT SEAT WIRE RH

OK: Go to Next Step

CHECK FRONT SEAT WIRE RH (SHORT TO B+)

Connect the negative (-) terminal cable to the battery.
Turn the engine switch on (IG).

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

Standard voltage

TESTER CONNECTION SPECIFIED CONDITION

Tester Connection	Condition	Specified Condition
T4-6 (PS) - Body ground	Engine switch on (IG)	Below 1 V
T4-7 (VPS) - Body ground	Engine switch on (IG)	Below 1 V
T4-15 (GPS) -Body ground	Engine switch on (IG)	Below 1 V

Fig 1: Checking Front Seat Wire RH (Short To B+)

Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

NG: REPAIR OR REPLACE FRONT SEAT WIRE RH

OK: Go to Next Step

CHECK FRONT SEAT WIRE RH (OPEN)

Turn the engine switch off.
Disconnect the negative (-) terminal cable from the battery, and wait for at least 90 seconds.
Using a service wire, connect terminals 1 (GPS) and 3 (VPS), and connect terminals 2 (PS) and 3 (VPS) of connector C.
NOTE: Do not forcibly insert the service wire into the terminals of the connector when connecting the wire.

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

Standard resistance

TESTER CONNECTION SPECIFIED CONDITION

Tester Connection	Condition	Specified Condition
T4-6 (PS) - T4-7 (VPS)	Always	Below 1 Ω
T4-7 (VPS) - T4-15 (GPS)	Always	Below 1 Ω

Fig 2: Checking Front Seat Wire RH (Open)

Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

NG: REPAIR OR REPLACE FRONT SEAT WIRE RH

OK: Go to Next Step

CHECK FRONT SEAT WIRE RH (SHORT TO GROUND)

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
T4-6 (PS) - Body ground	Always	1 MΩ or higher
T4-7 (VPS) - Body ground	Always	1 MΩ or higher
T4-15 (GPS) - Body ground	Always	1 MΩ or higher

Fig 3: Checking Front Seat Wire RH (Short To Ground)

NG: REPAIR OR REPLACE FRONT SEAT WIRE RH

OK: Go to Next Step

CHECK FRONT SEAT WIRE RH (SHORT)

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

Standard resistance

TESTER CONNECTION SPECIFIED CONDITION

Tester Connection	Condition	Specified Condition
T4-6 (PS) - T4-15 (GPS)	Always	1 MΩ or higher
T4-7 (VPS) - T4-15 (GPS)	Always	1 MΩ or higher

Fig 4: Checking Front Seat Wire RH (Short)

NG: REPAIR OR REPLACE FRONT SEAT WIRE RH

OK: Go to Next Step

CHECK DTC
1. Connect the connectors to the occupant classification ECU and the occupant classification sensor.
2. Connect the negative (-) terminal cable to the battery.
3. Turn the engine switch on (IG).
4. Clear the DTCs stored in the occupant classification ECU (See DTC CHECK / CLEAR ).
5. Clear the DTCs stored in the center airbag sensor assembly (See DTC CHECK/CLEAR ).
6. Turn the engine switch off.
7. Turn the engine switch on (IG).
8. Check the DTCs (See DTC CHECK / CLEAR ).
  OK: DTCs B1774 and B1775 are not output.
  
  HINT:
  
  Codes other than B1774 and B1775 may be output at this time, but they are not related to this check.
OK: USE SIMULATION METHOD TO CHECK (See TERMINALS OF ECU )

NG: Go to Next Step
REPLACE OCCUPANT CLASSIFICATION SENSOR (FRONT SEAT CUSHION ASSEMBLY)
1. Turn the engine switch off.
2. Disconnect the negative (-) terminal cable from the battery, and wait for at least 90 seconds.
3. Replace the front seat cushion assembly (with occupant classification ECU and occupant classification sensor) (See REMOVAL ).
  HINT:
  
  Perform the inspection using parts from a normal vehicle if possible.
4. Connect the negative (-) terminal cable to the battery.
5. Turn the engine switch on (IG).
6. Clear the DTCs stored in the occupant classification ECU (See DTC CHECK / CLEAR ).
7. Clear the DTCs stored in the center airbag sensor assembly (See DTC CHECK/CLEAR )
8. Turn the engine switch off.
9. Turn the engine switch on (IG).
10. Check the DTCs (See DTC CHECK / CLEAR ).
  OK: DTC B1774 and B1775 are not output.
  
  HINT:
  
  Codes other than B1774 and B1775 may be output at this time, but they are not related to this check.
PERFORM ZERO POINT CALIBRATION
1. Connect the intelligent tester to the DLC3.
2. Turn the engine switch on (IG).
3. Using the intelligent tester, perform the zero point calibration (See INITIALIZATION ).
4. Turn the engine switch off.
5. Turn the engine switch on (IG).
6. Clear the DTCs stored in the memory (See DTC CHECK / CLEAR ).
  HINT:
  
  If DTC is not cleared at this time, past DTC will remain.
CHECK DTC
HINT:

Check that the zero point calibration is completed normally. If any of the following conditions is met, DTC B1797 will be output (Refer to INITIALIZATION )
- Zero point calibration is performed when the conditions for the calibration are not satisfied.
- Zero point calibration has failed.
1. Turn the engine switch on (IG).
2. Clear the DTCs stored in the occupant classification ECU (See DTC CHECK / CLEAR ).
3. Clear the DTCs stored in the center airbag sensor assembly (See DTC CHECK/CLEAR ).
4. Turn the engine switch off.
5. Turn the engine switch on (IG).
6. Check the DTCs (See DTC CHECK/CLEAR ).
  OK: DTC B1797 is not output.
NG: GO TO DTC B1797

OK: Go to Next Step
PERFORM SENSITIVITY CHECK
1. Perform the sensitivity check (See INITIALIZATION ).
NEXT: END