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Service bulletins for the 2021 Toyota Sienna

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.

176 on file from NHTSA, as of 2026-10-19.

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By component

By trouble code

Only bulletins with component: Backup camera are shown. Show all

Bulletins, newest first
T-TT-0725-232023-04-17. Service bulletin. BACK OVER PREVENTION. TT: Some 2021- 2023 Sienna HV vehicles may duplicate an abnormal noise (Growl, Humming and/or other) from the Hybrid T/A at various vehicle speeds and normal drive conditions. Please contact TAS for diagnostic instructions to aid in resolution of the condition.
T-TT-0646-212021-04-19. Service bulletin. BACK OVER PREVENTION. TT: Confirm the scraping noise is coming from the front of the vehicle and not the rear. If the condition occurs from the front of the vehicle, verify the vehicle meets ALL the following criteria: 1) Mileage is under 5,000 miles 2) Vehicle has not had previous front brake repairs performed 3) Vehicle has not had prior adjustments to the dust cover 4) Confirm there is Rotor and Dust Cover contact. See photo. If the vehicle meets the criteria above, please create a TAS case and include photos of the contact between the dust cover and rotor. DO NOT make any adjustments to dust cover. TAS will provide further instruction. If it is a Sunday or holiday, continue with diagnosis and repair, save all parts and details (including pictures), and contact TAS at the next available opportunity.
T-TT-0599-20 Rev2021-04-19. Service bulletin. ELECTRICAL SYSTEM; BACK OVER PREVENTION. 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.
T-TT-0599-20 Rev2021-02-16. Service bulletin. BACK OVER PREVENTION:SOFTWARE. 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.
T-SB-0107-202020-11-30. Service bulletin. BACK OVER PREVENTION. TSB: 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 Techstream ECU flash reprogramming process and outlines use of 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 Techstream ECU flash reprogramming process.

The summaries are NHTSA's. Each bulletin's page links NHTSA's copy of the manufacturer's document.