# Service bulletin T\-SB\-0021\-25 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: 11015496 - Published by NHTSA: 2025\-03\-11 - Manufacturer's number: T\-SB\-0021\-25 - Manufacturer's date: 2025\-02\-10 - Campaign id or software version: T\-SB\-0021\-25 - NHTSA component: ENGINE ## NHTSA's summary Flash 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. ## The document - [NHTSA's copy of the document (PDF)](https://static.nhtsa.gov/odi/tsbs/2025/MC-11015496-0001.pdf) - [If that address does not open, try this one](https://static.nhtsa.gov/odi/tsbs/2025/MC-11015496-9999.pdf) The document is the manufacturer's. This site does not hold it. ## Components Engine ## Vehicles listed - 2025 TOYOTA 4RUNNER I\-FORCE MAX HYBRID - 2023 to 2025 TOYOTA BZ4X - 2023 to 2025 TOYOTA COROLLA - 2022 to 2025 TOYOTA COROLLA CROSS - 2023 to 2025 TOYOTA COROLLA CROSS HYBRID - 2023 to 2025 TOYOTA COROLLA HYBRID - 2023 to 2025 TOYOTA CROWN - 2025 TOYOTA CROWN SIGNIA - 2023 to 2025 TOYOTA GR COROLLA - 2024 to 2025 TOYOTA GRAND HIGHLANDER - 2024 to 2025 TOYOTA GRAND HIGHLANDER HYBRID - 2024 to 2025 TOYOTA HIGHLANDER - 2024 to 2025 TOYOTA HIGHLANDER HYBRID - 2025 TOYOTA LAND CRUISER HYBRID - 2021 to 2025 TOYOTA MIRAI - 2023 to 2025 TOYOTA PRIUS - 2025 TOYOTA PRIUS PLUG\-IN HYBRID - 2023 to 2024 TOYOTA PRIUS PRIME - 2025 TOYOTA RAV4 PLUG\-IN HYBRID - 2021 to 2024 TOYOTA RAV4 PRIME - 2023 to 2025 TOYOTA SEQUOIA HYBRID - 2021 to 2025 TOYOTA SIENNA HYBRID - 2024 to 2025 TOYOTA TACOMA - 2024 to 2025 TOYOTA TACOMA HYBRID - 2021 to 2025 TOYOTA TUNDRA - 2022 to 2025 TOYOTA TUNDRA HYBRID - 2021 to 2024 TOYOTA VENZA HYBRID - 2025 TOYOTA VENZA HYBRID - 2022 to 2025 TOYOTA redundant 86 - 2024 TOYOTA redundant LAND CRUISER ## Recalls for the same vehicles and component - [2026241](/recalls/tc/2026241.md), 2026-05-20: Engine - [26V320000](/recalls/nhtsa/26V320000.md), 2026-05-20: ENGINE AND ENGINE COOLING:ENGINE:HARD PARTS INTERNAL/MECHANICAL - [2025614](/recalls/tc/2025614.md), 2025-11-06: Engine - [25V767000](/recalls/nhtsa/25V767000.md), 2025-11-06: ENGINE AND ENGINE COOLING:ENGINE:HARD PARTS INTERNAL/MECHANICAL - [2024304](/recalls/tc/2024304.md), 2024-05-30: Engine - [24V381000](/recalls/nhtsa/24V381000.md), 2024-05-30: ENGINE AND ENGINE COOLING:ENGINE:HARD PARTS INTERNAL/MECHANICAL ## 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. - [26TC03](/bulletins/11037196.md), 2026-09-09, Service campaign: ENGINE. TECHNICAL INSTRUCTIONS FOR EMISSION NONCOMPLIANCE RECALL 26TC03 Certain 2022 – 2025 Model Year RAV4 Incorrect Mass Air Flow Sensor Reading - [26TC03](/bulletins/11037195.md), 2026-09-09, Service campaign: ENGINE. In wet conditions, water contacting the radiator in the subject vehicles after idling for an extended period can create steam that can cause an incorrect engine sensor reading. This can lead to a warning light, a rough\-running engine, or a potential engine stall while idling or operating at low speeds. - [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. - [26TC03](/bulletins/11036128.md), 2026-08-12, Service bulletin: ENGINE. TECHNICAL INSTRUCTIONS FOR EMISSION NONCOMPLIANCE RECALL 26TC03 Certain 2022 – 2025 Model Year RAV4 Incorrect Mass Air Flow Sensor Reading - [26TC03](/bulletins/11036123.md), 2026-08-12, Service bulletin: ENGINE. TECHNICAL INSTRUCTIONS FOR EMISSION NONCOMPLIANCE RECALL 26TC03 Certain 2022 – 2025 Model Year RAV4 Incorrect Mass Air Flow Sensor Reading - [26TC03](/bulletins/11036122.md), 2026-08-12, Service campaign: ENGINE. In wet conditions, water contacting the radiator in the subject vehicles after idling for an extended period can create steam that can cause an incorrect engine sensor reading. This can lead to a warning light, a rough\-running engine, or a potential engine stall while idling or operating at low speeds. - [26TE03](/bulletins/11033404.md), 2026-06-04, Warranty extension: ENGINE. Although the Mirai Electric Heater Assemblies are 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. Under this program, Toyota is providing additional coverage for repairs related to Mirai electric heater assembly potentially becoming inoperative. - [26TE03](/bulletins/11033403.md), 2026-06-04, Service bulletin: ENGINE. TECHNICAL INSTRUCTIONS FOR 26TE03 ELECTRIC HEATER SUB\-ASSEMBLY REPLACEMENT CERTAIN 2021 \- 2024 MIRAI JSON: [/v1/bulletins/11015496](/v1/bulletins/11015496) [Report an error on this page](https://github.com/wenmar-pro/wenmar-open/issues/new?template=data_correction.yml&title=Data%20correction%3A%20Service%20bulletin%20T-SB-0021-25&page=https%3A%2F%2Fopen.wenmarpro.com%2Fbulletins%2F11015496&vehicle=Service%20bulletin%20T-SB-0021-25)