Toyota 4Runner: Front Passenger Side Seat Belt Warning Light Malfunction

Toyota 4Runner Service Manual / Vehicle Interior / Seat Belt / Seat Belt Warning System / Front Passenger Side Seat Belt Warning Light Malfunction

DESCRIPTION

When the ignition switch is ON, the occupant detection ECU sends a signal to the airbag sensor assembly to indicate the state of the front seat inner belt assembly RH and also whether the front passenger seat is occupied. The airbag sensor assembly sends those signals to the combination meter assembly via CAN communication. The combination meter assembly illuminates, blinks or turns off the seat belt warning light on the combination meter assembly in accordance with these signals.

HINT:

The seat belt warning light on the combination meter assembly is used for both the driver seat and front passenger seat.

WIRING DIAGRAM

CAUTION / NOTICE / HINT

NOTICE:

The seat belt warning system uses the CAN communication system. First, confirm that there is no malfunction in the CAN communication system. Refer to the How to Proceed with Troubleshooting procedure (See page
).

PROCEDURE

1.	CHECK DTC OUTPUT (OCCUPANT CLASSIFICATION SYSTEM)

(a) Clear DTCs (See page ).

(b) Recheck for DTCs (See page ).

Result	Proceed to
DTC is not output	A
DTC is output	B

GO TO OCCUPANT CLASSIFICATION SYSTEM

2.	CHECK DTC OUTPUT (AIRBAG SYSTEM)

(a) Clear DTCs (See page ).

(b) Recheck for DTCs (See page ).

Result	Proceed to
DTC is not output	A
DTC is output	B

GO TO AIRBAG SYSTEM

3.	READ VALUE USING TECHSTREAM

(a) Connect the Techstream to the DLC3.

(b) Turn the ignition switch to ON.

(d) Enter the following menus: Body Electrical / Occupant Detection / Data List.

(e) Read the Data List according to the display on the Techstream.

Occupant Detection

Tester Display	Measurement Item/Range	Normal Condition	Diagnostic Note
Passenger Buckle SW	Front passenger side buckle switch / Unset, Set or NG	Unset: Front passenger side seat belt unfastened Set: Front passenger side seat belt fastened NG: Condition undetermined	-

Tester Display

Measurement Item/Range

Normal Condition

Diagnostic Note

Passenger Buckle SW

Front passenger side buckle switch / Unset, Set or NG

Unset: Front passenger side seat belt unfastened

Set: Front passenger side seat belt fastened

NG: Condition undetermined

Result

Result	Proceed to
Unset or Set is displayed on the Techstream screen according to the front passenger seat belt condition	A
Unset or Set is not displayed normally on the Techstream screen according to the front passenger seat belt condition	B
NG is displayed on the Techstream screen	C

REPLACE FRONT SEAT INNER BELT ASSEMBLY RH

REPLACE OCCUPANT DETECTION ECU

4.	READ VALUE USING TECHSTREAM

(a) Connect the Techstream to the DLC3.

(b) Turn the ignition switch to ON.

(d) Enter the following menus: Body Electrical / SRS Airbag / Data List.

(e) Read the Data List according to the display on the Techstream.

SRS Airbag

Tester Display	Measurement Item/Range	Normal Condition	Diagnostic Note
Right side Buckle SW	Front RH side seat belt buckle switch / Unset, Set or NG	Unset: Seat belt unfastened Set: Seat belt fastened NG: Condition undetermined	-

Tester Display

Measurement Item/Range

Normal Condition

Diagnostic Note

Right side Buckle SW

Front RH side seat belt buckle switch / Unset, Set or NG

Unset: Seat belt unfastened

Set: Seat belt fastened

NG: Condition undetermined

Result

Result	Proceed to
Unset or Set is displayed on the Techstream screen according to the front passenger seat belt condition	A
Unset or Set is not displayed normally on the Techstream screen according to the front passenger seat belt condition NG is displayed on the Techstream screen	B

USE SIMULATION METHOD TO CHECK

REPLACE AIRBAG SENSOR ASSEMBLY

Driver Side Seat Belt Warning Light does not Operate

DESCRIPTION When the ignition switch is turned to ON, the center airbag sensor transmits front seat inner belt LH state signals to the combination meter through the CAN. If the driver side seat b ...

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