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 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 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 B1790 is not output.
  
  HINT:
  
  Codes other than DTC B1790 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 CONNECTORS
1. Turn the engine switch off.
2. Disconnect the negative (-) terminal cable from the battery.
3. Check that the connectors are properly connected to the occupant classification ECU and the center airbag sensor assembly.
  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 center airbag sensor assembly and the occupant classification ECU.
2. Check that the connectors (on the center airbag sensor assembly side and occupant classification ECU side) are not damaged.
  OK: The connectors are not deformed or damaged.
NG: REPAIR OR REPLACE WIRE HARNESS

OK: Go to Next Step

CHECK OCCUPANT CLASSIFICATION SYSTEM CIRCUIT (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
T4-11 (FSR+) - Body ground	Engine switch on (IG)	Below 1V
T4-12 (FSR-) - Body ground	Engine switch on (IG)	Below 1V

Fig 1: Checking Occupant Classification System Circuit (Short To B+)

Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

NG: Go to step 13

OK: Go to Next Step

CHECK OCCUPANT CLASSIFICATION SYSTEM CIRCUIT (OPEN)

Turn the engine switch off.
Disconnect the negative (-) terminal cable from the battery.
with Rear side airbag:
Using a service wire, connect terminals 16 (FSP+) and 24 (FSP-) of connector B.

NOTE: Do not forcibly insert a service wire into the terminals of the connector when connecting the wire.
without Rear side airbag:
Using a service wire, connect terminals 12 (FSP+) and 13 (FSP-) of connector B.

NOTE: Do not forcibly insert a 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
T4-11 (FSR+) - T4-12 (FSR-)	Always	Below 1 Ω

Fig 2: Checking Occupant Classification System Circuit (Open)

Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

NG: Go to step 14

OK: Go to Next Step

CHECK OCCUPANT CLASSIFICATION SYSTEM CIRCUIT (SHORT)

Disconnect the service wire from connector B.

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

Standard resistance

TESTER CONNECTION SPECIFIED CONDITION

Tester Connection	Condition	Specified condition
T4-11 (FSR+) - T4-12 (FSR-)	Always	1 MΩ or higher

Fig 3: Checking Occupant Classification System Circuit (Short)

Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

NG: Go to step 15

OK: Go to Next Step

CHECK OCCUPANT CLASSIFICATION SYSTEM CIRCUIT (SHORT TO GROUND)

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

Standard resistance

TESTER CONNECTION SPECIFIED CONDITION

Tester Connection	Condition	Specified condition
T4-11 (FSR+) - Body ground	Always	1 MΩ or higher
T4-12 (FSR-) - Body ground	Always	1 MΩ or higher

Fig 4: Checking Occupant Classification System Circuit (Short To Ground)

Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

NG: Go to step 16

OK: Go to Next Step

RECHECK DTC
1. Connect the connectors to the occupant classification ECU and the center airbag sensor assembly.
2. Connect the intelligent tester to the DLC3.
3. Connect the negative (-) terminal cable to the battery.
4. Turn the engine switch on (IG).
5. Clear the DTCs stored in the occupant classification ECU (See DTC CHECK / CLEAR ).
6. Clear the DTCs stored in the center airbag sensor assembly (See DTC CHECK/CLEAR ).
7. Turn the engine switch off.
8. Turn the engine switch on (IG).
9. Using the intelligent tester, check the DTCs of the occupant classification ECU (See DTC CHECK / CLEAR ).
  OK: DTC B1790 is not output.
  
  HINT:
  
  Codes other than DTC B1790 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 OCCUPANT CLASSIFICATION ECU
1. Connect the intelligent tester to the DLC3.
2. Turn the engine switch on (IG).
3. Using the intelligent tester, save the ECU data from the ECU which has been installed on the vehicle (See HOW TO PROCEED WITH TROUBLESHOOTING ).
4. Turn the engine 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 engine switch on (IG).
9. Using the intelligent tester, load the previous ECU data stored into the new ECU (See HOW TO PROCEED WITH TROUBLESHOOTING ). 0) Turn the engine switch off.
10. Turn the engine switch off.
11. Turn the engine switch on (IG).
12. Clear the DTCs stored in the memory (See DTC CHECK / CLEAR ).
  HINT:
  
  If the DTCs are not cleared at this time, past DTCs will remain.
RECHECK 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. Using the intelligent tester, check the DTCs of the occupant classification ECU (See DTC CHECK / CLEAR ).
  OK: DTC B1790 is not output.
  
  HINT:
  
  Codes other than DTC B1790 may be output at this time, but they are not related to this check.
OK: Go to step 12

NG: Go to Next Step
REPLACE CENTER AIRBAG SENSOR 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 center airbag sensor assembly (See REMOVAL ).
PERFORM SENSITIVITY CHECK
1. Perform the sensitivity check (See INITIALIZATION ).
NEXT: END

CHECK FLOOR WIRE NO. 2 (SHORT TO B+)

Turn the engine switch off.
Disconnect the negative (-) terminal cable from the battery, and wait for at least 90 seconds.
Disconnect the front seat wire RH connector from the floor wire No. 2.
Connect the negative (-) terminal cable to the battery, and wait for at least 2 seconds.
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
MT2-1 (FSR+) - Body ground	Engine switch on (IG)	Below 1 V
MT2-4 (FSR-) - Body ground	Engine switch on (IG)	Below 1 V

Fig 5: Checking Floor Wire No. 2 (Short To B+)

Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

NG: REPAIR OR REPLACE FLOOR WIRE NO. 2

OK: REPAIR OR REPLACE FRONT SEAT WIRE RH

CHECK FLOOR WIRE NO. 2 (OPEN)

Disconnect the front seat wire RH connector from the floor wire No. 2.
HINT:

The service wire has already been inserted into connector B.

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

Standard resistance

TESTER CONNECTION SPECIFIED CONDITION

Tester Connection	Condition	Specified condition
MT2-1 (FSR+) - MT2-4 (FSR-)	Always	Below 1 Ω

Fig 6: Checking Floor Wire No. 2 (Open)

NG: REPAIR OR REPLACE FLOOR WIRE NO. 2

OK: REPAIR OR REPLACE FRONT SEAT WIRE RH

CHECK FLOOR WIRE NO. 2 (SHORT)

Disconnect the front seat wire RH connector from the floor wire No. 2.

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

Standard resistance

TESTER CONNECTION SPECIFIED CONDITION

Tester Connection	Condition	Specified condition
MT2-1 (FSR+) - MT2-4 (FSR-)	Always	1 MΩ or higher

Fig 7: Checking Floor Wire No. 2 (Short)

NG: REPAIR OR REPLACE FLOOR WIRE NO. 2

OK: REPAIR OR REPLACE FRONT SEAT WIRE RH

CHECK FLOOR WIRE NO. 2 (SHORT TO GROUND)

Disconnect the front seat wire RH connector from the floor wire No. 2.

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

Standard resistance

TESTER CONNECTION SPECIFIED CONDITION

Tester Connection	Condition	Specified condition
MT2-1 (FSR+) - Body ground	Always	1 MΩ or higher
MT2-4 (FSR-) - Body ground	Always	1 MΩ or higher

Fig 8: Checking Floor Wire No. 2 (Short To Ground)

NG: REPAIR OR REPLACE FLOOR WIRE NO. 2

OK: REPAIR OR REPLACE FRONT SEAT WIRE RH