Toyota Tundra. Manual — part 2623

Courtesy of TOYOTA MOTOR SALES, U.S.A., INC.

DIAGNOSIS SYSTEM

1. SYMPTOM SIMULATION

HINT:

The most difficult case in troubleshooting is when no problem symptoms occur. In such a case, a
thorough problem analysis must be carried out. A simulation of the same or similar conditions and
environment in which the problem occurred in the customer's vehicle should be carried out. No matter
how much skill or experience a technician has, troubleshooting without confirming the problem
symptoms will lead to important repairs being overlooked and mistakes or delays.

a. Vibration method: When vibration seems to be the major cause.

HINT:

Perform the simulation method only during the primary check period (for approximately 6 seconds
after the ignition switch is turned ON).

1. Slightly vibrate the part of the sensor considered to be the cause of the problem with your

fingers and check whether the malfunction occurs.

HINT:

Shaking the relays too strongly may result in open relays.

2. Slightly shake the connector vertically and horizontally.

3. Slightly shake the wire harness vertically and horizontally.

The connector joint and fulcrum of the vibration are the major areas to be checked
thoroughly.

b. Simulation method for DTC B1795: Turn the ignition switch from OFF to ON, hold it for 10

seconds, and then turn it back to OFF. Repeat this procedure 50 times in a row.

HINT:

DTC B1795 is output if the occupant classification ECU receives the ignition switch lock-on-lock
signal 50 times in a row when a malfunction occurs in the power circuit for the occupant
classification system.

2009 Toyota Tundra

2009 RESTRAINTS Supplemental Restraint System - Tundra

Fig. 202: Identifying Vibration Method
Courtesy of TOYOTA MOTOR SALES, U.S.A., INC.

2. FUNCTION OF PASSENGER AIRBAG ON/OFF INDICATOR

a. Initial check

1. Turn the ignition switch ON.

2. The passenger airbag ON/OFF indicator (ON and OFF) comes on for approximately 4

seconds, then goes off for approximately 2 seconds.

3. Approximately 6 seconds after the ignition switch is turned ON, the passenger airbag ON/

OFF indicator will be ON/OFF depending on the conditions listed below.

except Double Cab:

INDICATOR CONDITION TABLE

for Double Cab:

PASSENGER AIRBAG CUTOFF SWITCH POSITION TABLE

Front Seat Passenger

ON

Indicator

OFF

Indicator

SRS Warning

Light

Adult seated

ON

OFF

OFF

Child seated/Child restraint system set

OFF

ON

OFF

Vacant

OFF

OFF

OFF

Passenger occupant classification system
failure

OFF

ON

ON

2009 Toyota Tundra

2009 RESTRAINTS Supplemental Restraint System - Tundra

HINT:



The passenger airbag ON/OFF indicator operates based on the timing table below in
order to check the indicator light circuit.

Fig. 203: Identifying Passenger Airbag ON/OFF Indicator Flash-Pattern
Courtesy of TOYOTA MOTOR SALES, U.S.A., INC.



When the occupant classification system has trouble, both the SRS warning light and
the passenger airbag ON/OFF indicator (OFF) come on. In this case, check the DTCs
in the airbag system first.

Front Seat Passenger

Passenger Airbag

Cutoff Switch Position

ON

Indicator

OFF

Indicator

SRS

Warning

Light

Adult seated

ON

ON

OFF

OFF

OFF

OFF

ON

OFF

Passenger airbag cut-off

switch system failure

OFF

ON

ON

Child seated/Child
restraint system set

ON

OFF

ON

OFF

OFF

OFF

ON

OFF

Passenger airbag cut-off

switch system failure

OFF

ON

ON

Vacant

ON

OFF

OFF

OFF

OFF

OFF

ON

OFF

Passenger airbag cut-off

switch system failure

OFF

ON

ON

Passenger occupant
classification system
failure

ON

OFF

ON

ON

OFF

OFF

ON

ON

Passenger airbag cut-off

switch system failure

OFF

ON

ON

2009 Toyota Tundra

2009 RESTRAINTS Supplemental Restraint System - Tundra

3. CHECK PASSENGER AIRBAG ON/OFF INDICATOR

a. Turn the ignition switch ON.

b. Check that the passenger airbag ON/OFF indicator (ON and OFF) comes on for approximately 4

seconds, then goes off for approximately 2 seconds.

HINT:

Refer to the table in the previous step regarding the passenger airbag ON/OFF indicator when
approximately 6 seconds have elapsed after the ignition switch is turned ON.

DTC CHECK/CLEAR

1. CHECK DTC

HINT:



When DTC B1650/23 is detected as a result of troubleshooting the airbag system, troubleshoot the
occupant classification system.



Use the Techstream to read and clear DTCs, otherwise the DTCs cannot be read and cleared.

a. Connect the Techstream to the DLC3.

b. Turn the ignition switch ON.

c. Turn the Techstream on.

d. Enter the following menus: Body Electrical/Occupant Detection/Trouble Codes.

Fig. 204: Identifying Passenger Airbag ON/OFF Indicator
Courtesy of TOYOTA MOTOR SALES, U.S.A., INC.

2009 Toyota Tundra

2009 RESTRAINTS Supplemental Restraint System - Tundra