Toyota Tundra. Manual — part 2621

Fig. 198: Identifying Occupant Classification System Components (3 Of 3)
Courtesy of TOYOTA MOTOR SALES, U.S.A., INC.

SYSTEM DIAGRAM

2009 Toyota Tundra

2009 RESTRAINTS Supplemental Restraint System - Tundra

Fig. 199: Identifying Occupant Classification System Diagram
Courtesy of TOYOTA MOTOR SALES, U.S.A., INC.

SYSTEM DESCRIPTION

1. GENERATION DESCRIPTION

a. The occupant classification system determines whether the front passenger seat is occupied by an

adult or child (with child seat) or is unoccupied, based on the load that is applied to the front
passenger seat and whether the seat belt is buckled. The system restricts the deployment of the front
passenger airbag, front passenger side airbag, and front passenger seat belt pretensioner in
accordance with this judgment. The result is informed to the driver through the front airbag
ON/OFF indicator illumination.

2. SYSTEM CONFIGURATION

a. This system consists of the occupant classification ECU, occupant detection sensors, front airbag

ON/OFF indicator, passenger side seat belt buckle switches, and center airbag sensor.

3. OCCUPANT DETECTION SENSOR

a. The occupant detection sensors are installed on 4 brackets, which connect the seat rail and the seat

2009 Toyota Tundra

2009 RESTRAINTS Supplemental Restraint System - Tundra

frame. The resistance values of these sensors, which vary in accordance with the load that acts on
the brackets, are transmitted to the occupant classification ECU as signals. Upon receipt of the
signals, the ECU determines the front passenger seat occupant conditions.

Fig. 200: Identifying Occupant Detection Sensors
Courtesy of TOYOTA MOTOR SALES, U.S.A., INC.

HOW TO PROCEED WITH TROUBLESHOOTING

HINT:



Use these procedures to troubleshoot the occupant classification system.



*: Use the Techstream.

1. VEHICLE BROUGHT TO WORKSHOP

2. CUSTOMER PROBLEM ANALYSIS

a. Confirm customer problem symptoms (see HOW TO PROCEED WITH

TROUBLESHOOTING ).

3. CHECK FOR DTC*

a. Check for DTCs and note any codes that are output (see DTC CHECK/CLEAR ).

b. Check for DTCs (see DTC CHECK/CLEAR ).

c. Recheck for DTCs (see DTC CHECK/CLEAR ). Based on the DTCs output above, try to force

output of the same CAN communication system DTC or occupant classification system DTC by
simulating the symptoms indicated by the DTC.

Result

2009 Toyota Tundra

2009 RESTRAINTS Supplemental Restraint System - Tundra

RESULT TABLE

B: Go to DIAGNOSTIC TROUBLE CODE TABLE

C: Go to DIAGNOSTIC TROUBLE CODE TABLE

A: Go to next step

4. PROBLEM SYMPTOMS TABLE

a. Refer to PROBLEM SYMPTOMS TABLE .

Result

RESULT TABLE

B: Go to step 6

A: Go to next step

5. OVERALL ANALYSIS AND TROUBLESHOOTING*

a. See TERMINALS OF ECU

b. See DATA LIST/ACTIVE TEST

6. REPAIR OR REPLACE

7. CONFIRMATION TEST

NEXT: END

INITIALIZATION

HINT:

Perform the zero point calibration and sensitivity check if any of the following conditions apply.



The occupant classification ECU is replaced.

Result

Proceed to

DTC is not output

A

CAN communication system DTC is output

B

Occupant classification system DTC is output

C

Result

Proceed to

Fault is not listed in problem symptoms table

A

Fault is listed in problem symptoms table

B

NOTE:

Make sure that the front passenger seat is not occupied before performing the
operation.

2009 Toyota Tundra

2009 RESTRAINTS Supplemental Restraint System - Tundra