Last Modified: 04-05-2023 6.11:8.1.0 Doc ID: RM100000000VJZ6
Model Year Start: 2016 Model: Sienna Prod Date Range: [12/2015 -           ]
Title: SEAT BELT: SEAT BELT WARNING SYSTEM: Driver Side Seat Belt Warning Light does not Operate; 2016 - 2020 MY Sienna [12/2015 -        ]

Driver Side Seat Belt Warning Light does not Operate

DESCRIPTION

When the ignition switch is ON, the center airbag sensor assembly transmits front seat inner belt status signals to the combination meter assembly through CAN. If the driver seat belt is not fastened, the combination meter assembly blinks the driver side seat belt warning light. If the seat belt is fastened, the warning light goes off.

WIRING DIAGRAM

CAUTION / NOTICE / HINT

NOTICE:

he seat belt warning system uses the CAN communication system. First, confirm that there are no malfunctions in the CAN communication system. Refer to How to Proceed with Troubleshooting (See page 2016 - 2020 MY Sienna [12/2015 -        ]; SEAT BELT: SEAT BELT WARNING SYSTEM: HOW TO PROCEED WITH TROUBLESHOOTING ).

PROCEDURE

1.

CHECK DTC OUTPUT (AIRBAG SYSTEM)

(a) Clear the DTCs (See page 2016 - 2020 MY Sienna [12/2015 -        ]; SUPPLEMENTAL RESTRAINT SYSTEMS: AIRBAG SYSTEM: DTC CHECK / CLEAR ).

(b) Check for DTCs (See page 2016 - 2020 MY Sienna [12/2015 -        ]; SUPPLEMENTAL RESTRAINT SYSTEMS: AIRBAG SYSTEM: DTC CHECK / CLEAR ).

Result

Result

Proceed to

DTCs are not output

A

DTCs are output

B

B

GO TO AIRBAG SYSTEM

A

2.

READ VALUE USING TECHSTREAM (LEFT SIDE BUCKLE SW)

(a) Connect the Techstream to the DLC3.

(b) Turn the ignition switch to ON.

(c) Turn the Techstream 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

Left side Buckle SW

Driver side seat belt buckle switch/Unset, Set or NG

Unset: Driver side seat belt unfastened

Set: Driver side seat belt fastened

NG: Data not determined

-

Result

Result

Proceed to

Unset or Set is displayed on the Techstream according to the driver seat belt condition

A

Unset or Set is not displayed correctly on the Techstream according to the driver seat belt condition

B

NG is displayed on the Techstream

C

B

REPLACE FRONT SEAT INNER BELT ASSEMBLY LH

C

REPLACE CENTER AIRBAG SENSOR ASSEMBLY

A

3.

REPLACE MAIN BODY ECU

(a) Temporarily replace the main body ECU with a new or known good one (See page 2016 - 2020 MY Sienna [12/2015 -        ]; POWER DISTRIBUTION: MAIN BODY ECU: REMOVAL ).

NEXT

4.

CHECK SEAT BELT WARNING LIGHT

(a) Check the operation of the seat belt warning light (See page 2016 - 2020 MY Sienna [12/2015 -        ]; SEAT BELT: SEAT BELT WARNING SYSTEM: ON-VEHICLE INSPECTION ).

OK:

The seat belt warning light operates normally.

OK

END (MAIN BODY ECU WAS DEFECTIVE)

NG

REPLACE COMBINATION METER ASSEMBLY