Toyota Tundra Service Manual: Trouble in Passenger Airbag ON/OFF Indicator

Toyota Tundra Service Manual / Vehicle Interior / Supplemental Restraint Systems / Occupant Classification System / Trouble in Passenger Airbag ON/OFF Indicator

DESCRIPTION

The passenger airbag ON/OFF indicator consists of the center airbag sensor, occupant detection ECU, hazard warning switch assembly, and 4 occupant classification sensors. This system controls the passenger airbag deployment according to the occupancy condition of the front passenger seat, and also displays those detected conditions.

WIRING DIAGRAM

CAUTION / NOTICE / HINT

NOTICE:

After turning the ignition switch off, waiting time may be required before disconnecting the cable from the negative (-) battery terminal. Therefore, make sure to read the disconnecting the cable from the negative (-) battery terminal notices before proceeding with work (Click here ).
When disconnecting the cable from the negative (-) battery terminal while performing repairs, some systems need to be initialized after the cable is reconnected (Click here ).

PROCEDURE

1.	RETIGHTEN FRONT SEAT ASSEMBLY RH BOLT

(a) Turn the ignition switch off.

(b) Loosen the 4 installation bolts of the front seat RH.

for Manual Seat (Click here ).
for Power Seat (Click here ).

Torque:

37 N·m {377 kgf·cm, 27 ft·lbf}

2.	PERFORM ZERO POINT CALIBRATION

(a) Connect the Techstream to the DLC3.

(b) Turn the ignition switch to ON, and wait for at least 60 seconds.

OK:

Zero point calibration is completed using tester.

END

3.	READ VALUE USING TECHSTREAM (FRONT PASSENGER SIDE BUCKLE SWITCH)

(a) Turn the ignition switch to ON, and wait for at least 60 seconds.

(b) Using the Techstream, read the "Data List" (Click here ).

Occupant Detection:

Tester Display

Measure Item / Range

Normal Condition

Diagnostic Note

Passenger Buckle SW

Passenger side buckle switch / Set, Unset or NG

Set: Front passenger side seat belt is fastened

Unset: Front passenger side seat belt is unfastened

NG: Front passenger side seat belt is malfunctioning

OK:

Display changed correctly according to operation of buckle switch.

GO TO STEP 8

4.	READ VALUE USING TECHSTREAM (OCCUPANT DETECTION SENSOR)

(a) Fasten the front passenger side seat belt.

(b) Turn the ignition switch to ON, and wait for at least 60 seconds.

Occupant Detection:

Tester Display	Test Part	Control Range	Diagnostic Note
FL Sensor Voltage	Front left sensor voltage/ Min.: 0 V Max.: 19.8 V	0 to 4.7 V	-
FR Sensor Voltage	Front right sensor voltage/ Min.: 0 V Max.: 19.8 V	0 to 4.7 V	-
RL Sensor Voltage	Rear left sensor voltage/ Min.: 0 V Max.: 19.8 V	0 to 4.7 V	-
RR Sensor Voltage	Rear right sensor voltage/ Min.: 0 V Max.: 19.8 V	0 to 4.7 V	-
FL Sensor Weight Info	Front left sensor weight information/ Min.: -17 kg (-37.48 lb) Max.: 27 kg (59.52 lb)	-17 to 27 kg (-37.48 to 59.52 lb)	-
FR Sensor Weight Info	Front right sensor weight information/ Min.: -17 kg (-37.48 lb) Max.: 27 kg (59.52 lb)	-17 to 27 kg (-37.48 to 59.52 lb)	-
RL Sensor Weight Info	Rear left sensor weight information/ Min.: -17 kg (-37.48 lb) Max.: 37 kg (81.57 lb)	-17 to 37 kg (-37.48 to 81.57 lb)	-
RR Sensor Weight Info	Rear right sensor weight information/ Min.: -17 kg (-37.48 lb) Max.: 37 kg (81.57 lb)	-17 to 37 kg (-37.48 to 81.57 lb)	-
Total Weight Information	Total weight information/ Min.: -68 kg (-149.91 lb) Max.: 128 kg (282.19 lb)	-68 to 128 kg (-149.91 to 282.19 lb)	-

Result	Proceed to
Display is as specified in normal condition	A
Display is not as specified in normal condition (for Power Seat)	B
Display is not as specified in normal condition (for Manual Seat)	C

REPLACE OCCUPANT CLASSIFICATION ECU

5.	REPLACE FRONT SEAT FRAME WITH ADJUSTER ASSEMBLY RH

(a) Turn the ignition switch off.

(b) Disconnect the negative (-) terminal cable from the battery, and wait for at least 90 seconds.

HINT:

Perform the inspection using parts from a normal vehicle when possible.

6.	PERFORM ZERO POINT CALIBRATION

(a) Connect the negative (-) terminal cable to the battery, and wait for at least 2 seconds.

(b) Connect the Techstream to the DLC3.

(d) Using the Techstream, perform the zero point calibration (Click here ).

7.	PERFORM SENSITIVITY CHECK

(a) Using the Techstream, perform the sensitivity check (Click here ).

Standard range:

27 to 33 kg (59.5 to 72.8 lb)

END

8.	CHECK CONNECTORS

(a) Disconnect the connectors from the occupant classification ECU and front seat inner belt RH.

(b) Check that the connectors (on the occupant classification ECU side and front seat inner belt RH side) are not damaged.

OK:

Connectors are not deformed or damaged.

REPLACE NO. 2 FLOOR WIRE

9.	REPLACE FRONT SEAT INNER BELT ASSEMBLY RH

(a) Turn the ignition switch off.

(b) Disconnect the negative (-) terminal cable from the battery, and wait for at least 90 seconds.

(d) Connect the negative (-) terminal cable to the battery, and wait for at least 2 seconds.

10.	PERFORM ZERO POINT CALIBRATION

(a) Connect the Techstream to the DLC3.

(b) Turn the ignition switch to ON, and wait for at least 60 seconds.

11.	PERFORM SENSITIVITY CHECK

(a) Using the Techstream, perform the sensitivity check (Click here ).

Standard range:

27 to 33 kg (59.5 to 72.8 lb)

END

Terminals Of Ecu

Seat Position Sensor

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Toyota Tundra Service Manual: Trouble in Passenger Airbag ON/OFF Indicator

Terminals Of Ecu

Seat Position Sensor

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