Last Modified: 04-05-2023 6.11:8.1.0 Doc ID: RM100000000VJZ7
Model Year Start: 2016 Model: Sienna Prod Date Range: [12/2015 -           ]
Title: SEAT BELT: SEAT BELT WARNING SYSTEM: Front Passenger Side Seat Belt Warning Light Malfunction; 2016 - 2020 MY Sienna [12/2015 -        ]

Front Passenger Side Seat Belt Warning Light Malfunction

DESCRIPTION

The occupant classification ECU detects the state of the front seat inner belt assembly RH and load sensor when the front passenger side seat is occupied with the ignition switch ON. If the front passenger side seat belt is not fastened, the front passenger side seat belt warning light on the combination meter assembly blinks. If the seat belt is fastened, the warning light goes off.

WIRING DIAGRAM

PROCEDURE

1.

CHECK DTC OUTPUT (OCCUPANT CLASSIFICATION SYSTEM)

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

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

Result

Result

Proceed to

DTCs are not output

A

DTCs are output

B

B

GO TO OCCUPANT CLASSIFICATION SYSTEM

A

2.

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

3.

READ VALUE USING TECHSTREAM (OCCUPANT DETECTION)

(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 / 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 seat belt buckle switch/Unset, Set or NG

Unset: Front passenger side seat belt unfastened

Set: Front passenger side seat belt fastened

NG: Data not determined

-

Result

Result

Proceed to

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

A

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

B

NG is displayed on the Techstream

C

B

REPLACE FRONT SEAT INNER BELT ASSEMBLY RH

C

REPLACE OCCUPANT CLASSIFICATION ECU

A

4.

READ VALUE USING TECHSTREAM (RIGHT 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

Right side Buckle SW

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

Unset: Front passenger side seat belt unfastened

Set: Front passenger side seat belt fastened

NG: Data not determined

-

Result

Result

Proceed to

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

A

  • Unset or Set is not displayed correctly on the Techstream according to the front passenger seat belt condition
  • NG is displayed on the Techstream

B

A

USE SIMULATION METHOD TO CHECK

(See page 2016 MY Sienna [12/2015 - 08/2016]; INTRODUCTION: HOW TO TROUBLESHOOT ECU CONTROLLED SYSTEMS: HOW TO PROCEED WITH TROUBLESHOOTING 2017 MY Sienna [08/2016 - 11/2017]; INTRODUCTION: HOW TO TROUBLESHOOT ECU CONTROLLED SYSTEMS: HOW TO PROCEED WITH TROUBLESHOOTING 2018 - 2020 MY Sienna [11/2017 -        ]; INTRODUCTION: HOW TO TROUBLESHOOT ECU CONTROLLED SYSTEMS: HOW TO PROCEED WITH TROUBLESHOOTING )

B

REPLACE CENTER AIRBAG SENSOR ASSEMBLY