Toyota bulletin T-SB-0021-25 REV1
What it saysFlash reprogramming allows the Electronic Control Unit (ECU) software to be updated without replacing the ECU. NHTSA’s full summary ↓
Toyota filed this with NHTSA as a service bulletin dated Oct 30, 2026, received Nov 11, 2026, about the engine — 1 document under this number: T-SB-0021-25 Rev1. It names 98 model years (2021–2027). 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.
Get the next Toyota bulletin for your model by email Weekly, only when something new is filed. Nothing else; one-click unsubscribe.
What the bulletin says
Source: NHTSA's summary of the manufacturer's communicationFlash reprogramming allows the Electronic Control Unit (ECU) software to be updated without replacing the ECU. Flash calibration updates for specific vehicle models/ECUs are released as field-fix procedures described in individual Service Bulletins. This bulletin details the Global Techstream+ (GTS+) ECU flash reprogramming procedures and outlines use of the Technical Information System (TIS) and the Calibration Update Wizard+ (CUW+). To ensure the correct ECU software is installed, ECUs will require a Security Signature before the ECU will initialize the flash reprogramming sequence. This bulletin also details the process for acquiring a Security Signature from TIS during the GTS+ ECU flash reprogramming process.
Document filed under this number
| Document | Kind | Dated | NHTSA id | At NHTSA |
|---|---|---|---|---|
| T-SB-0021-25 Rev1 | Service bulletin | Oct 30, 2026 | 11039881 |
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 themand 43 more on this site: 2025 Toyota Mirai, 2024 Toyota Mirai, 2027 Toyota Prius, 2026 Toyota Prius, 2025 Toyota Prius, 2024 Toyota Prius, 2023 Toyota Prius, 2024 Toyota Prius Prime, 2023 Toyota Prius Prime, 2026 Toyota RAV4, 2025 Toyota RAV4, 2024 Toyota RAV4 Prime, 2023 Toyota RAV4 Prime, 2022 Toyota RAV4 Prime, 2021 Toyota RAV4 Prime, 2026 Toyota Sequoia, 2025 Toyota Sequoia, 2024 Toyota Sequoia, 2023 Toyota Sequoia, 2026 Toyota Sienna, 2025 Toyota Sienna, 2024 Toyota Sienna, 2023 Toyota Sienna, 2022 Toyota Sienna, 2021 Toyota Sienna, 2026 Toyota Tacoma, 2025 Toyota Tacoma, 2024 Toyota Tacoma, 2026 Toyota Tundra, 2025 Toyota Tundra, 2024 Toyota Tundra, 2023 Toyota Tundra, 2022 Toyota Tundra, 2021 Toyota Tundra, 2024 Toyota Venza, 2023 Toyota Venza, 2022 Toyota Venza, 2021 Toyota Venza, 2027 Toyota bZ, 2026 Toyota bZ, 2025 Toyota bZ4X, 2024 Toyota bZ4X, 2023 Toyota bZ4X.
Also filed against model years this site has no page for: 2027 Toyota 4RUNNER; 2027 Toyota 4RUNNER I-Force MAX Hybrid; 2027 Toyota GR Corolla; 2026 Toyota GR86; 2027 Toyota Grand Highlander; 2027 Toyota Grand Highlander Hybrid; 2027 Toyota Mirai; 2027 Toyota RAV4 Hybrid; 2027 Toyota RAV4 Plug-IN Hybrid; 2027 Toyota Sequoia Hybrid; 2027 Toyota Sienna Hybrid; 2027 Toyota Tacoma; 2027 Toyota Tacoma Hybrid; 2027 Toyota Tundra; 2027 Toyota Tundra Hybrid.
A vehicle page’s bulletin list shows the newest few communications filed against that model year; the count there is every one.
Email me new Toyota bulletins for one of these models
A weekly email, sent only in a week when Toyota files something new with NHTSA for the model you pick — service bulletins, campaigns, warranty extensions, over-the-air notices, every model year. Nothing else is sent; one-click unsubscribe in every message. Separate from recall alerts.
What owners reported
Source: NHTSA complaint databaseOwners of the 83 model years this bulletin names have filed 4,739 complaints with NHTSA since 2015. 956 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.
On the 2023 Toyota Tundra, the 39 owners who gave an odometer reading for Engine reported it at a median of 39,660 miles. That figure is one model year’s, not the whole range this bulletin covers — medians from different model years are not averaged.
Upon starting the vehicle on 8/6/2025 i received multiple warnings: advanced ultrasonic detecting and ranging system malfunction, Pre-Collision system malfunction, Parking Brake system malfunction, Check engine ECM malfunction, Vehicle stability control system malfunction Secondary collison brake system malfunction, It now take almost a…
2025 Toyota Tundra · Engine · filed with NHTSA Aug 7, 2025 · ODI 11678976
Intermittently as I press on the brake, the engine loses power, engine feels like it is going to die and the charge meter on the dash display drops to no charge. Right before the engine dies the engine regains charge on the dash display charge meter and the engine returns to normal. So far the engine has never totally died on me yet
2024 Toyota Crown · Engine · filed with NHTSA Oct 28, 2025 · ODI 11696024
COMPONENT/SYSTEM FAILURE: Engine - Catastrophic engine failure due to oil starvation on August 4, 2025. FA24 engine consumed excessive oil without triggering oil pressure warning light or low oil level indicator. Oil was changed at 500 miles after purchase and topped off on July 12, 2025. Engine failed 23 days later with no warning.
2022 Toyota GR86 · Engine · filed with NHTSA Sep 19, 2025 · ODI 11688386
In depth: 2023 Toyota Corolla Cross engine problems → · 2024 Toyota Tundra engine problems → · 2023 Toyota Tundra engine problems → · 2022 Toyota Tundra engine problems →
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 group87 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-0071-26 | Service bulletin | Oct 30, 2026 | Some 2025 – 2026 model year Crown, Crown Signia, RAV4 Hybrid, and Sienna Hybrid vehicles with an A25A engine may experience a MIL ON with Di… |
| 26TE04 | Warranty extension | Oct 16, 2026 | This Customer Support Program provides coverage as it applies to the engine turbocharger assemblies on certain 2022 – 2025 Model Year Tundra… |
| T-SB-0060-26 | Service bulletin | Oct 8, 2026 | Some 2022 – 2025 model year Tundra and Tundra Hybrid and 2023 – 2025 Sequoia Hybrid vehicles may exhibit an MIL ON condition with one or mor… |
| T-SB-0034-26 REV1 | Service bulletin | Sep 16, 2026 | Some 2025 – 2026 model year Camry HV vehicles may exhibit a MIL ON condition with Diagnostic Trouble Code (DTC) P0A1B94… |
| 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… |
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-SB-0021-25 REV1 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-SB-0021-25 REV1 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-SB-0021-25 REV1 cover?
The manufacturer filed it against 98 model years: 2026 Toyota 4Runner, 2025 Toyota 4Runner, 2027 Toyota C-HR, 2026 Toyota C-HR, 2027 Toyota Camry, 2026 Toyota Camry and more. Whether one particular vehicle is affected is a matter of its VIN and its build, not its model year alone.