Service bulletin T-TT-0726-23

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.

The communication, as NHTSA indexes it (as of 2026-10-19)
Type	Service bulletin
NHTSA id	10241394
Published by NHTSA	2023-08-28
Manufacturer's number	T-TT-0726-23
Manufacturer's date	2023-07-10
NHTSA component	BACK OVER PREVENTION; ENGINE AND ENGINE COOLING

NHTSA's summary

TT: Some 2021 - 2023 Highlander HV, RAV4 HV and Sienna HV vehicles equipped with Rear Motor Generator, MGR (Q610), may duplicate an abnormal noise (Drone, Growl, Humming, and/or other) from the MGR at various vehicle speeds and normal drive conditions. Please contact TAS for diagnostic instructions to aid in resolution of the condition.

The document

The document is the manufacturer's. This site does not hold it. NHTSA files a document at one of these two addresses; we have not asked NHTSA which.

Components

Driver assistance, Engine, Backup camera

Vehicles listed
TOYOTA HIGHLANDER	2021, 2022, 2023
TOYOTA RAV4	2021, 2022, 2023
TOYOTA redundant SIENNA	2021 to 2023

Listing a model year does not mean every vehicle of it is concerned: the document says which.

Recalls for the same vehicles and component
25V744000	2025-10-30. BACK OVER PREVENTION:DISPLAY FUNCTION

A recall listed here may apply to some of the same vehicles. Only the manufacturer can say whether it applies to one vehicle.

Other bulletins for the same vehicles and component
T-TT-0728-23	2023-08-28. Service bulletin. TT: This issue is currently under investigation. Please create TAS case and attach a store all health check. Please contact TAS for further instructions. If it is a weekend or a holiday, continue with diagnosis and repair. Please save all parts/ or details and contact TAS on the next available workday.
TSB-0041-23	2023-07-31. Service bulletin. TSB: Some 2023 model year GR Corolla, RAV4, RAV4 Hybrid, RAV4 Prime, and Venza Hybrid vehicles with multimedia version older than 1564 may exhibit one or more of the following conditions: ?Head unit rebooting (does not affect backup camera). ?Head unit does not boot up (does not affect backup camera). ?Display screen flickers (does not affect backup camera). ?Map is not displayed. ?User profile enhancements. ?The French ?Share ETA? screen is not completely in French. ?Incoming call ringing continues even after ignoring or ending the call. Some 2023 model year Prius and Prius Prime vehicles with multimedia version older than 1586 may exhibit one or more of the following conditions: ?Head unit rebooting (does not affect backup camera). ?Head unit does not boot up (does not affect backup camera). ?Display screen flickers (does not affect backup camera). A software update is now available to address these conditions
T-TT-0726-23	2023-04-17. Service bulletin. TT: Some 2021 - 2023 Highlander HV, RAV4 HV and Sienna HV vehicles equipped with Rear Motor Generator, MGR (Q610), may duplicate an abnormal noise (Drone, Growl, Humming, and/or other) from the MGR at various vehicle speeds and normal drive conditions. Please contact TAS for diagnostic instructions to aid in resolution of the condition.
T-TT-0724-23	2023-04-17. Service bulletin. TT: Some 19-21MY RAV4 Japan produced vehicles in Puerto Rico only exhibit a squeak type noise from the front suspension over bumps. Japan produced vehicles can be identified by VINs beginning with J.
T-SB-0014-23	2023-04-17. Service bulletin. TSB: Some 2019 ? 2021 model year RAV4 and RAV4 Hybrid and 2021 model year RAV4 Prime vehicles may exhibit a rattle noise from the sliding roof assembly when it is in the tilted open position while driving over a bumpy road. Follow the Repair Procedure in this bulletin to address this condition.
T-SB-0115-22 Rev	2023-04-17. Service bulletin. TSB: Some 2019 ? 2022 model year Avalon, 2018 ? 2023 model year Camry, 2017 ? 2022 model year Highlander, and 2017 ? 2020 model year Sienna vehicles equipped with a 2GR-FKS engine may exhibit a knocking noise from the vacuum pump at idle.
TTT061620	2022-06-21. Service bulletin. TT: Some customers may experience an abnormal steering sensation (?pulling?, ?drifting?), which may be more pronounced after a cold soak. The steering angle value displayed in Techstream may be greater than +3° off when the steering wheel is held straight. Every time the vehicle?s battery is disconnected or discharged, the Steering Angle Neutral Point Memorization and the Steering Sensor Zero Point Calibration must be performed. These steps are consistent with Step 3 and 4 of the ?BEFORE INSPECTION? section of the Pre-Delivery Service Check Sheet
T-SB-0084-21 Rev	2022-04-18. Service bulletin. TSB: Some 2019 ? 2022 model year RAV4 and RAV4 Hybrid and 2021 ? 2022 model year RAV4 Prime vehicles may exhibit a sloshing or splashing noise from inside one or more door panels when driving, opening and/or closing a door, and/or braking. This condition is caused by a cavity wax/debris/substance that may block door drain holes and restrict water from draining properly. Follow the Repair Procedure in this bulletin to address this condition
T-TT-0616-20 Rev	2021-04-19. Service bulletin. TT: Some customers may experience an abnormal steering sensation (?pulling?, ?drifting?), which may be more pronounced after a cold soak. The steering angle value displayed in Techstream may be greater than +3° off when the steering wheel is held straight. Every time the vehicle?s battery is disconnected or discharged, the Steering Angle Neutral Point Memorization and the Steering Sensor Zero Point Calibration must be performed.
T-TT-0599-20 Rev	2021-04-19. Service bulletin. TT: Vehicle control apps might not operate as expected at times due to preconditions (normal operating parameters) not being established, vehicle settings and/or network/cellular coverage concerns.