Inspection Procedure

WARNING: This page is about a different car, the 2008 Toyota Tundra. However, it is still accessible from the selected car via links, so may be relevant.

NOTE: After the ignition switch is turned OFF, the navigation system requires approximately 90 seconds to record various types of memory and settings. As a result, after turning the ignition switch OFF, wait 90 seconds or more before disconnecting the cable from the negative (-) battery terminal.

CHECK FOR DTC
1. Turn the ignition switch ON, and wait for at least 60 seconds.
2. Clear any DTCs stored in the memory (see DTC CHECK/CLEAR ).
  HINT:
  - First clear DTCs stored in the occupant classification ECU and then in the center airbag sensor.
  - Use the Techstream to clear the DTCs of the occupant classification ECU, otherwise the DTCs cannot be cleared.
3. Turn the ignition switch OFF, and wait for at least 10 seconds.
4. Turn the ignition switch ON, and wait for at least 60 seconds.
5. Using the Techstream, check for DTCs of the occupant classification ECU (see DTC CHECK/CLEAR ).
  OK: DTC B1794 is not output.
  
  HINT:
  
  DTCs other than DTC B1794 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 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 center airbag sensor, occupant detection sensors and occupant classification ECU.
  OK: Connectors are properly connected.
NG: CONNECT CONNECTOR

OK: Go to next step
CHECK CONNECTOR
1. Check that the connectors (on the occupant classification ECU side) are not damaged (see ELECTRONIC CIRCUIT INSPECTION PROCEDURE ).
  OK: Connectors are not deformed or damaged.
NG: REPLACE HARNESS OR CONNECTOR

OK: Go to next step

CHECK HARNESS AND CONNECTOR (SOURCE VOLTAGE)

Turn the ignition switch OFF.
Disconnect the negative (-) terminal cable from the battery, and wait for at least 90 seconds.
Disconnect the Y2*1 or Q11*2 ECU connector.
HINT:

*1: for Power Seat

*2: for Manual Seat
Connect the negative (-) terminal cable to the battery, and wait for at least 2 seconds.
Turn the ignition switch ON, and wait for at least 60 seconds.

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

Fig 1: Identifying Occupant Classification ECU Connector Terminals

Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

Standard resistance:

for Power Seat

TESTER CONNECTION SPECIFIED CONDITION TABLE

Tester Connection	Condition	Specified Condition
Y2-3 (GND) - Body ground	Always	Below 1 Ω

for Manual Seat

TESTER CONNECTION SPECIFIED CONDITION TABLE

Tester Connection	Condition	Specified Condition
Q11-3 (GND) - Body ground	Always	Below 1 Ω

Standard voltage:

for Power Seat

TESTER CONNECTION SPECIFIED CONDITION TABLE

Tester Connection	Switch Condition	Specified Condition
Y2-1 (+B) - Body ground	Ignition switch ON	11 to 14 V
Y2-7 (IG) - Body ground	Ignition switch ON	11 to 14 V

for Manual Seat

TESTER CONNECTION SPECIFIED CONDITION TABLE

Tester Connection	Switch Condition	Specified Condition
Q11-1 (+B) - Body ground	Ignition switch ON	11 to 14 V
Q11-7 (IG) - Body ground	Ignition switch ON	11 to 14 V

NG: REPLACE HARNESS OR CONNECTOR

OK: Go to next step

CHECK FOR DTC
1. Turn the ignition switch OFF.
2. Disconnect the negative (-) terminal cable from the battery, and wait for at least 90 seconds.
3. Connect the connectors to the occupant classification ECU.
4. Connect the negative (-) terminal cable to the battery, and wait for at least 2 seconds.
5. Turn the ignition switch ON, and wait for at least 60 seconds.
6. Clear any DTCs stored in the memory (see DTC CHECK/CLEAR ).
  HINT:
  - First clear DTCs stored in the occupant classification ECU and then in the center airbag sensor.
  - Use the Techstream to clear the DTCs of the occupant classification ECU, otherwise the DTCs cannot be cleared.
7. Turn the ignition switch OFF, and wait for at least 10 seconds.
8. Turn the ignition switch ON, and wait for at least 60 seconds.
9. Using the Techstream, check for DTCs of the occupant classification ECU (see DTC CHECK/CLEAR ).
  OK: DTC B1794 is not output.
  
  HINT:
  
  DTCs other than DTC B1794 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 )
REPLACE OCCUPANT CLASSIFICATION ECU
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 occupant classification ECU.
  - for Manual Seat (see FRONT SEAT ASSEMBLY (FOR MANUAL SEAT) )
  - for Power Seat (see FRONT SEAT ASSEMBLY (FOR POWER SEAT) )
  HINT:
  
  Perform the inspection using parts from a normal vehicle when possible.
PERFORM ZERO POINT CALIBRATION
1. Connect the negative (-) terminal cable to the battery, and wait for at least 2 seconds.
2. Connect the Techstream to the DLC3.
3. Turn the ignition switch ON, and wait for at least 60 seconds.
4. Using the Techstream, perform the zero point calibration (see INITIALIZATION ).
PERFORM SENSITIVITY CHECK
1. Using the Techstream, perform the sensitivity check (see INITIALIZATION ).
  Standard range:
  
  27 to 33 kg (59.5 to 72.8 lb)
NEXT: END