Toyota bulletin T-TT-0771-25
What it saysSome 2021-2025 MY Highlander HV, Sienna HV, RAV4, and RAV4 HV, may exhibit an oil leak from the area where the camshaft cover, camshaft housing, and the timing chain covers meet. NHTSA’s full summary ↓
Toyota filed this with NHTSA as a service bulletin dated Jan 28, 2025, received Feb 12, 2025, about the engine. It names 15 model years (2021–2025). A service bulletin is not a safety recall: it is the manufacturer telling its dealers how to diagnose or repair a condition, and whether the work is paid for depends on the warranty in force. Quoting the number at a service desk can save a diagnosis.
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What the bulletin says
Source: NHTSA's summary of the manufacturer's communicationSome 2021-2025 MY Highlander HV, Sienna HV, RAV4, and RAV4 HV, may exhibit an oil leak from the area where the camshaft cover, camshaft housing, and the timing chain covers meet. This is typically seen on the exhaust side of the engine.
Document filed under this number
| Document | Kind | Dated | NHTSA id | At NHTSA |
|---|---|---|---|---|
| T-TT-0771-25 | Service bulletin | Jan 28, 2025 | 11014205 |
The summary is NHTSA’s abstract of the document, as filed under 49 CFR 579.5. One communication is usually filed as several documents — the bulletin, a dealer notice, an owner letter — and the number on any of them finds this page. A PDF link is shown only once NHTSA’s own server has been seen to serve that document; the rest are checked over the following nights. Quote the number at a service desk; it is what the dealer’s system is keyed on.
Model years it names
Source: as the manufacturer filed themA vehicle page’s bulletin list shows the newest few communications filed against that model year; the count there is every one.
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What owners reported
Source: NHTSA complaint databaseOwners of the 15 model years this bulletin names have filed 2,576 complaints with NHTSA since 2015. 239 of them name Engine — the same broad component group this bulletin is filed under. NHTSA groups complaints coarsely, so that means the same area of the vehicle, not necessarily the same fault.
I purchased the car last July. Up to December, the car performed fine. Starting in December when I used the car heater repeatedly due to subzero temperatures, I noticed a burning smell coming from the vents. I was afraid that the engine or car would catch fire. I called the Tansky Toyota dealership and was told to bring the car in.
2022 Toyota RAV4 · Engine · filed with NHTSA Apr 22, 2023 · ODI 11518482
The contact owns a 2023 Toyota Rav4 Hybrid. The contact stated while driving 15-20 MPH, the vehicle unexpectedly stopped. There were no warning lights illuminated. The contact attempted to restart the vehicle several times. After the failure, the engine and brake warning lights illuminated.
2023 Toyota RAV4 · Engine · filed with NHTSA Nov 22, 2024 · ODI 11626769
The contact owns a 2025 Toyota Highlander. The contact stated while driving at an undisclosed speed, there was an abnormally strong odor entering the cabin of the vehicle through the vents. The windows were rolled down due to the obnoxious odor.
2025 Toyota Highlander · Engine · filed with NHTSA Jan 21, 2026 · ODI 11712542
A complaint is one owner’s account, not a defect finding, and a bulletin is not a recall. Nothing here says this bulletin was issued because of these complaints, or that the repair it describes fixed them. Complaint files on this site begin in 2015.
More bulletins about the engine
Source: same model, same component group46 other manufacturer communications filed against these Toyota models under the same component group (engine), newest first. The eight newest are listed; the rest are on the Toyota list.
| Number | Kind | Dated | NHTSA’s summary |
|---|---|---|---|
| T-SB-0110-20 OBSOLETE | Service bulletin | Aug 20, 2026 | OBSOLETE NOTICE August 20, 2026: This bulletin is now obsolete. Please see T-SB-0051-26. |
| T-SB-0051-26 | Service bulletin | Aug 20, 2026 | This bulletin includes basic procedures for performing a rescue charge at battery on high voltage (HV) Ni-MH and Li-ion batteries. |
| 26TC03 | Service campaign | Aug 17, 2026 | In wet conditions, water contacting the radiator in the subject vehicles after idling for an extended period can create steam that can cause… |
| 24TE04 | Warranty extension | Aug 11, 2026 | This Customer Support Program provides coverage as it applies to Flow Shut-off Valve Coolant Leak on Certain 2019-2021 Avalon & Avalon HV, 2… |
| T-TT-0806-26 | Service bulletin | Jul 22, 2026 | State of Health (SOH): An estimate of battery health that is updated as the vehicle learns from operating and charging conditions over time.… |
| T-TT-0801-26 | Service bulletin | Apr 16, 2026 | Some Customers for the listed vehicles may have complaint of the following: unable to charge the vehicle using the supplied level 1 or 2 cha… |
| T-SB-0023-26 | Service bulletin | Apr 1, 2026 | Some customers may experience a rough running engine with a MIL ON P140018 DTC. Upon further inspection, a loose C90/C27 connector pin at th… |
| T-SB-0104-21 OBSOLETE | Service bulletin | Feb 27, 2026 | OBSOLETE NOTICE February 27, 2026: This bulletin is no longer applicable and is now obsolete. |
Quote the number at the service desk. It is what the dealer’s system is keyed on.
Every manufacturer communication NHTSA holds for Toyota, by the number printed on the letter.
Common questions
Source: NHTSA, 49 CFR 579.5Is Toyota T-TT-0771-25 a recall?
No. A service bulletin is a manufacturer communication filed with NHTSA under 49 CFR 579.5; a safety recall carries an NHTSA campaign number (two digits, a letter, six digits) and a federal duty to repair for free. Check the vehicle’s recalls by VIN at nhtsa.gov/recalls, or on its page here.
Is the T-TT-0771-25 repair free?
Not automatically. A service bulletin describes how to diagnose or repair a condition; who pays depends on the warranty in force, any extension, and the dealer. Quoting the number can save a diagnosis either way. Every Toyota warranty extension on file lists the ones Toyota has filed.
Which vehicles does T-TT-0771-25 cover?
The manufacturer filed it against 15 model years: 2025 Toyota Highlander, 2024 Toyota Highlander, 2023 Toyota Highlander, 2022 Toyota Highlander, 2021 Toyota Highlander, 2025 Toyota RAV4 and more. Whether one particular vehicle is affected is a matter of its VIN and its build, not its model year alone.