# Service bulletin T\-SB\-0031\-21

A bulletin is a manufacturer's communication to its dealers, as NHTSA indexes it. The summary is NHTSA's. The document is the manufacturer's: read it at NHTSA. A bulletin is not a recall, and listing a model year does not mean every vehicle of it is concerned.

- Type: Service bulletin
- NHTSA id: 10198144
- Published by NHTSA: 2021\-06\-21
- Manufacturer's number: T\-SB\-0031\-21
- Manufacturer's date: 2021\-05\-20
- NHTSA component: ENGINE; ELECTRICAL SYSTEM

## NHTSA's summary

TSB: Some 2021 model year Sienna Hybrid LE vehicles may exhibit a condition of inoperative remote functions from the app or key fob, such as remote engine start or door lock/unlock functions. Registering either, or both, the ?Remote Engine Starter Registration Status? and ?Remote Door Lock Function? may be necessary using Techstream to address this condition. Follow the Repair Procedure in this bulletin to address this condition.

## The document

- [NHTSA's copy of the document (PDF)](https://static.nhtsa.gov/odi/tsbs/2021/MC-10198144-0001.pdf)
- [If that address does not open, try this one](https://static.nhtsa.gov/odi/tsbs/2021/MC-10198144-9999.pdf)

The document is the manufacturer's. This site does not hold it.

## Components

Electrical system, Engine

## Vehicles listed

- 2021 TOYOTA SIENNA HYBRID

## Other bulletins for the same vehicles and component

- [T\-SB\-0110\-20 Rev2](/bulletins/11037202.md), 2026-09-09, Service bulletin: ENGINE. OBSOLETE NOTICE August 20, 2026: This bulletin is now obsolete. Please see T\-SB\-0051\-26.
- [T\-SB\-0051\-26](/bulletins/11037201.md), 2026-09-09, Service bulletin: ENGINE. This bulletin includes basic procedures for performing a rescue charge at battery on high voltage \(HV\) Ni\-MH and Li\-ion batteries.
- [24TE04](/bulletins/11037186.md), 2026-09-09, Warranty extension: ENGINE. Although the flow shut\-off valve is covered by Toyota’s New Vehicle Limited Warranty for 36 months or 36,000 miles \(whichever comes first\), we at Toyota care about the customers’ ownership experience. Toyota is providing coverage for repairs related to Flow Shut\-off Valve Coolant Leak.
- [22TE09](/bulletins/11033412.md), 2026-06-04, Warranty extension: ELECTRICAL SYSTEM. Although the HV Floor Under Wire Harness and Rear Traction Motor Cable is covered by Toyota’s New Vehicle Limited Warranty for 3 years or 36,000 miles \(whichever comes first\), we at Toyota care about the customers’ ownership experience. Toyota is providing extended coverage under this Customer Support Program for repairs related to excessive corrosion to the wire harness connections at the Rear Motor Generator. Excessive corrosion can cause AM Radio Static during certain drive cycles, or the vehicle may not start.
- [T\-SB\-0104\-21 Rev2](/bulletins/11029896.md), 2026-03-07, Service bulletin: ENGINE. OBSOLETE NOTICE February 27, 2026: This bulletin is no longer applicable and is now obsolete.
- [T\-SB\-0106\-22 Rev2](/bulletins/11028726.md), 2026-02-11, Service bulletin: ELECTRICAL SYSTEM. OBSOLETE NOTICE January 30, 2026: This bulletin is now obsolete. Please see T\-SB\-0001\-26.
- [T\-SB\-0001\-26](/bulletins/11028722.md), 2026-02-11, Service bulletin: ELECTRICAL SYSTEM. Some 2018 – 2024 model year Toyota vehicles equipped with a Premium Audio with Dynamic Navigation System require a Special Service Tool \(SST\) USB flash drive to update the map, points of interest, and system software.
- [22TE09](/bulletins/11028711.md), 2026-02-11, Warranty extension: ELECTRICAL SYSTEM. Although the HV Floor Under Wire Harness and Rear Traction Motor Cable is covered by Toyota’s New Vehicle Limited Warranty for 3 years or 36,000 miles \(whichever comes first\), we at Toyota care about the customers’ ownership experience. Toyota is providing extended coverage under this Customer Support Program for repairs related to excessive corrosion to the wire harness connections at the Rear Motor Generator. Excessive corrosion can cause AM Radio Static during certain drive cycles, or the vehicle may not start.
- [22TE09](/bulletins/11024081.md), 2025-10-08, Service bulletin: ELECTRICAL SYSTEM. TECHNICAL INSTRUCTIONS FOR CUSTOMER SUPPORT PROGRAM 22TE09 HV FLOOR UNDER WIRE HARNESS AND REAR TRACTION MOTOR CABLE CORROSION CERTAIN 2021 – 2024 MODEL YEAR SIENNA HYBRID
- [22TE09](/bulletins/11024080.md), 2025-10-08, Service campaign: ELECTRICAL SYSTEM. Although the HV Floor Under Wire Harness and Rear Traction Motor Cable is covered by Toyota’s New Vehicle Limited Warranty for 3 years or 36,000 miles \(whichever comes first\), we at Toyota care about the customers’ ownership experience. Toyota is providing extended coverage under this Customer Support Program for repairs related to excessive corrosion to the wire harness connections at the Rear Motor Generator. Excessive corrosion can cause AM Radio Static during certain drive cycles, or the vehicle may not start.

JSON: [/v1/bulletins/10198144](/v1/bulletins/10198144)

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