Inspection Procedure

WARNING: This page is about a different car, the 2008 Lexus IS F. 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 access 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 damage the seat or deform the seat rails. 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 CONNECTORS
1. Turn the engine switch off.
2. Disconnect the cable from the negative (-) battery terminal.
3. Check that the connectors are properly connected to the occupant classification ECU and the occupant classification sensor
  OK: The connectors are properly connected.
  
  HINT:
  
  If the connectors are not connected securely, reconnect the connectors and proceed to the next inspection
4. Disconnect the connectors from the occupant classification ECU and the occupant classification sensor
5. Check that the terminals of the connectors are not damaged
  OK: The terminals are not deformed or damaged.
NG: REPLACE FRONT SEAT WIRE RH

OK: Go to next step

CHECK FRONT SEAT WIRE RH (SHORT TO B+)

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

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

Standard Voltage

TESTER CONNECTION SPECIFIED CONDITION CHART

Tester Connection	Switch Condition	Specified Condition
T16-6 (PS) - Body ground	Engine switch on (IG)	Below 1 V
T16-7 (VPS) - Body ground	Engine switch on (IG)	Below 1 V
T16-15 (GPS) - Body ground	Engine switch on (IG)	Below 1 V

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

Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

NG: REPLACE FRONT SEAT WIRE RH

OK: Go to next step

CHECK FRONT SEAT WIRE RH (OPEN)

Turn the engine switch off.

Fig 2: Identifying Front Seat Wire RH (Open)
Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
Disconnect the cable from the negative (-) battery terminal.
Using SST, connect terminals 1 (GPS) and 3 (VPS), and connect terminals 2 (PS) and 3 (VPS) of connector C.
NOTE: Do not forcibly insert SST into the terminals of the connector when connecting the wire.

SST 09843-18040

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

Standard Resistance

TESTER CONNECTION SPECIFIED CONDITION CHART

Tester Connection	Condition	Specified Condition
T16-6 (PS) - T16-7 (VPS)	Always	Below 1 Ω
T16-7 (VPS) - T16-15 (GPS)	Always	Below 1 Ω

NG: REPLACE FRONT SEAT WIRE RH

OK: Go to next step

CHECK FRONT SEAT WIRE RH (SHORT TO GROUND)

Disconnect SST from connector C

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

Standard Resistance

TESTER CONNECTION SPECIFIED CONDITION CHART

Tester Connection	Condition	Specified Condition
T16-6 (PS) - Body ground	Always	1 MΩ or higher
T16-7 (VPS) - Body ground	Always	1 MΩ or higher
T16-15 (GPS) - Body ground	Always	1 MΩ or higher

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

NG: 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 CHART

Tester Connection	Condition	Specified Condition
T16-6 (PS) - T16-15 (GPS)	Always	1 MΩ or higher
T16-7 (VPS) - T16-15 (GPS)	Always	1 MΩ or higher

Fig 4: Identifying Front Seat Wire RH (Short)

NG: 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 cable to the negative (-) battery terminal.
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 for 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.
NG: Go to step 7

OK: USE SIMULATION METHOD TO CHECK (See DIAGNOSIS SYSTEM )
INSPECT OCCUPANT CLASSIFICATION SENSOR (FRONT SEAT CUSHION ASSEMBLY)
1. Turn the engine switch off.
2. Disconnect the cable from the negative (-) battery terminal.
3. Replace the front seat cushion assembly (with occupant classification ECU and occupant classification sensor) with a known good part (See REMOVAL ).
  HINT
  
  Perform an inspection using known good parts from another vehicle if possible.
4. Connect the cable to the negative (-) battery terminal.
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 Techstream to the DLC3
2. Turn the engine switch on (IG).
3. Using the Techstream, 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 for DTCs (See DTC CHECK / CLEAR )
  OK: DTC B1797 is not output.
NG: GO TO DTC B1797 (See DTC B1797 CALIBRATION MALFUNCTION )

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