Inspection Procedure

WARNING: This page is about a different car, the 2008 Scion xB. 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 to 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 DTC CHECK / CLEAR )
4. Turn the ignition switch to OFF.
5. Turn the ignition switch to ON.
6. Check for 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.
NG: Go to step 2

OK : USE SIMULATION METHOD TO CHECK (See DIAGNOSIS SYSTEM )
CHECK CONNECTION OF CONNECTOR
1. Turn the ignition switch to 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 center airbag sensor.
  OK:
  
  Connectors are properly connected.
NG : CONNECT CONNECTORS PROPERLY

OK: Go to next step
CHECK CONNECTOR
1. Disconnect the connectors from the center airbag sensor and the occupant classification ECU.
2. Check that the connectors (on the center airbag sensor side and occupant classification ECU side) are not damaged.
  OK:
  
  Connectors are not deformed or damaged.
NG : REPLACE HARNESS OR CONNECTOR

OK: Go to next step

CHECK OCCUPANT CLASSIFICATION SYSTEM CIRCUIT

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

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

Standard voltage

TESTER CONNECTION SPECIFIED VOLTAGE CONDITION CHART

Tester Connection	Switch Condition	Specified Condition
M2-11 (FSR+) - Body ground	Ignition switch ON	Below 1 V
M2-12 (FSR-) - Body ground	Ignition switch ON	Below 1 V

Turn the ignition switch to OFF.
Disconnect the negative (-) terminal cable from the battery, and wait for at least 90 second.
Using a service wire, connect terminals 12 (FSR+) and 13 (FSR-) of connector B.
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 RESISTANCE CONDITION CHART

Tester Connection	Condition	Specified Condition
M2-11 (FSR+) - M2-12 (FSR-)	Always	Below 1 Ω

Disconnect the service wire from connector B.

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

Standard resistance

TESTER CONNECTION SPECIFIED RESISTANCE CONDITION CHART

Tester Connection	Condition	Specified Condition
M2-11 (FSR+) - M2-12 (FSR-)	Always	1 MΩ or higher
M2-11 (FSR+) - Body ground
M2-12 (FSR-) - Body ground

Fig 1: Checking Occupant Classification System Circuit

Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

NG: Go to step 14

OK: Go to next step

CHECK FOR DTC
1. Connect the connectors to the occupant classification ECU and the center airbag sensor.
2. Connect an intelligent tester or Techstream to the DLC3.
3. Connect the negative (-) terminal cable to the battery.
4. Turn the ignition switch to ON.
5. Clear the DTCs stored in the occupant classification ECU (see DTC CHECK / CLEAR ).
6. Clear the DTCs stored in the center airbag sensor (see DTC CHECK / CLEAR ).
7. Turn the ignition switch to OFF.
8. Turn the ignition switch to ON.
9. Using the intelligent tester or Techstream, check for 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.
NG: Go to step 6

OK : USE SIMULATION METHOD TO CHECK (See DIAGNOSIS SYSTEM )
PERFORM REGISTRATION BEFORE ECU EXCHANGE
1. Connect an intelligent tester or Techstream to the DLC3.
2. Turn the ignition switch to ON.
3. Using the intelligent tester or Techstream, save the ECU data from the ECU which was installed on the vehicle (see REGISTRATION ).
REPLACE OCCUPANT CLASSIFICATION ECU
1. Turn the ignition switch to OFF.
2. Disconnect the negative (-) terminal cable from the battery, and wait for at least 90 seconds.
3. Replace the occupant classification ECU (see REMOVAL ).
4. Connect the negative (-) terminal cable to the battery.
PERFORM REGISTRATION AFTER ECU EXCHANGE
1. Turn the ignition switch to ON.
2. Using an intelligent tester or Techstream, load the previous ECU data stored in the tester into the new ECU (see REGISTRATION ).
PERFORM ZERO POINT CALIBRATION
1. Using an intelligent tester or Techstream, perform zero point calibration (see INITIALIZATION ).

CHECK FOR DTC

HINT:

Check that the zero point calibration is completed normally. If one 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.

Clear the DTCs stored in the occupant classification ECU (see DTC CHECK / CLEAR ).
Clear the DTCs stored in the center airbag sensor (see DTC CHECK / CLEAR ).
Turn the ignition switch to OFF.
Turn the ignition switch to ON.

Check for the DTCs of the occupant classification ECU (see DTC CHECK / CLEAR ).

Result

RESULT CHART

Result	Proceed to
No DTC output.	A
DTC B1790 is output.	B
DTC B1797 is output.	C

B: Go to step 12

C: Go TO DTC B1797

A: Go to next step

PERFORM SENSITIVITY CHECK
1. Perform the sensitivity check (see INITIALIZATION ).
NEXT : END
REPLACE CENTER AIRBAG SENSOR ASSEMBLY
1. Turn the ignition switch to OFF.
2. Disconnect the negative (-) terminal cable from the battery, and wait for at least 90 seconds.
3. Replace the center airbag sensor (see REMOVAL ).
4. Connect the negative (-) terminal cable to the battery.
PERFORM SENSITIVITY CHECK
1. Perform the sensitivity check (see INITIALIZATION ).
NEXT : END

CHECK NO. 2 FLOOR WIRE

Disconnect the front seat wire RH connector from the No. 2 floor wire.
Connect the negative (-) terminal cable to the battery.
Turn the ignition switch to ON.

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

Standard voltage

TESTER CONNECTION SPECIFIED VOLTAGE CONDITION CHART

Tester Connection	Switch Condition	Specified Condition
IM1-5 (FSR+) - Body ground	Ignition switch ON	Below 1 V
IM1-10 (FSR-) - Body ground	Ignition switch ON	Below 1 V

Turn the ignition switch to OFF.
Disconnect the negative (-) terminal cable from the battery, and wait for at least 90 seconds.
Using a service wire, connect terminals 12 (FSR+) and 13 (FSR-) of connector B.
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 RESISTANCE CONDITION CHART

Tester Connection	Condition	Specified Condition
IM1-5 (FSR+) - IM1-10 (FSR-)	Always	Below 1 Ω

Disconnect the service wire from connector B.

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

Fig 2: Checking No. 2 Floor Wire

Standard resistance

TESTER CONNECTION SPECIFIED RESISTANCE CONDITION CHART

Tester Connection	Condition	Specified Condition
IM1-5 (FSR+) - IM1-10 (FSR-)	Always	1 MΩ or higher
IM1-5 (FSR+) - Body ground
IM1-10 (FSR-) - Body ground

NG : REPLACE NO. 2 FLOOR WIRE

OK : REPLACE FRONT SEAT WIRE RH