2021 Toyota Sienna Hybrid

NHTSA received a petition on or about July 18, 2022, requesting that Federal Motor Vehicle Safety Standard (FMVSS) 141 be applied to all electric and hybrid vehicles operating in the United States. The petition can be reviewed at NHTSA.gov under ODI Number 11486072. FMVSS 141 establishes performance requirements for pedestrian alert sounds for motor vehicles. The standard applies to hybrid and electric vehicles that have a gross vehicle weight rating of 4,536 KG or less or are defined as low-speed vehicles. The standard became fully applicable to all such vehicles manufactured on or after March 1, 2021.On January 27, 2023, NHTSA opened Defect Petition (DP) 22-005 to evaluate the subject matter described in the petition. On June 24, 2023 and as supplemented on June 25, 2023, the petitioner notified NHTSA he was withdrawing his petition. The petitioner indicated that, based on his review of data, there is no justification for asserting potential benefits that could be derived from actions sought by my petition. Based on the petitioner's withdrawal, DP22-005 is closed. Closure of this DP does not represent a determination by NHTSA regarding the subject matter of the petition.

Vehicle safety SOS button is not functioning properly. When the SOS button is depressed in case of emergency, the vehicle notifies user at the emergency system is un operational. Toyota includes this for 10 years from the date purchase and my vehicle is a 2021 making this feature active till 2031. By having the SOS button nonfunctional occupants of the vehicle, which may rely on this feature may sustain injury or death by this feature not operating correctly in the event of an accident.

NHTSA ID

11752014

Incident

Jul 22, 2026

FAILURE: Blind spot monitor module failed due to a corroded internal electrical connector. The failure disabled both the Blind Spot Monitor (BSM) and Rear Cross-Traffic Alert (RCTA). Both remain inoperative. The failed component has not been replaced and is available for inspection. SAFETY RISK: Two active safety systems are disabled. The vehicle no longer warns of vehicles in the blind spot during lane changes, and no longer warns of cross traffic when backing out of parking spaces or driveways. WARNING LAMPS: Yes. Multiple warning lamps illuminated simultaneously in February 2026, including BSM and RCTA malfunction messages. No prior symptoms or gradual degradation. CONFIRMED BY DEALER: Yes. A Toyota dealer diagnosed the corroded connector as the cause. Repair quoted at approximately $2,500-$3,000. Repair not performed. INSPECTED BY MANUFACTURER: Diagnosed by a Toyota dealer. Goodwill assistance was requested from Toyota and declined, on the stated grounds that the vehicle had not been regularly serviced at a Toyota dealer. NOT A WEAR ITEM: A sealed electrical connector that corrodes to failure is a component defect. No step in the manufacturer's published maintenance schedule inspects, services, or protects this connector — no owner action could have prevented it, and service history has no bearing on a connector that no service procedure touches. Vehicle purchased new September 2021; failure occurred at approximately [XXX] of age. REQUEST: Request that ODI evaluate whether the BSM sensor and connector design used on this vehicle is inadequately sealed against moisture intrusion, resulting in premature failure of two active safety systems. INFORMATION REDACTED PURSUANT TO THE FREEDOM OF INFORMATION ACT (FOIA), 5 U.S.C. 552(B)(6)

NHTSA ID

11750096

Incident

Feb 11, 2026

FAILURE: Brake control system. Vehicle intermittently surges forward while braking at low speed, most often through a curve — the brakes momentarily release and the vehicle lurches before braking resumes. Appears to occur during the transition between regenerative and friction braking. Vehicle available for inspection. SAFETY RISK: Unpredictable momentary loss of braking at low speed, in parking lots, residential streets and curves where pedestrians and other vehicles are close. Driver cannot anticipate it. WARNING LAMPS: None. No lamp, no message, no stored trouble code. Present since early in ownership; purchased new September 2021. CONFIRMED BY DEALER: No. Reported to a Toyota dealer in 2022 under warranty. Dealer test drove, could not reproduce the intermittent condition, took no action. Also reported in writing to Toyota in August 2022; no substantive response. MANUFACTURER REMEDY: In May 2024 Toyota issued TSB T-SB-0047-24, a brake control module software update for this exact low-speed braking condition on 2021-2022 Sienna Hybrids. Warranty had lapsed, so it was applied at owner expense in late June 2026 at ~156,000 miles. The defect persists after Toyota's own remedy. The surge still occurs, including within the past week at ~157,000 miles. REQUEST: A TSB is not a recall — owners are not notified, and the software remedy did not eliminate the defect on this vehicle. Request that ODI evaluate whether this condition warrants a defect investigation and recall.

NHTSA ID

11750094

Incident

Jul 13, 2026

Car surged as brakes were applied when stopping. Very dangerous. Could have easily rear-ended another vehicle. Surge was immediate and occurred when brake was being applied. Not confirmed yet, but another driver of vehicle told me of having similar problems when braking this car. Very scary. No warnings or messsages.

NHTSA ID

11747761

Incident

Jul 1, 2026

Unexpected failure of the acceleration pedal to accelerate from a complete stop to a go at an intersection. The electric vehicle (EV) motor began accelerating up to about 3 mph than instantly had a failure to accelerate, even with the gas pedal continuously pushed to the floor. After about 4 to 5 seconds the engine kicked on and began accelerating. The failure seemed to occur during the EV motor swapping over to the gas powered engine. This has been the fourth occurrence and can be extremely dangerous at intersections with oncoming traffic. No fault codes or check engine lights came on.

NHTSA ID

11746943

Incident

Jun 27, 2026

1. The rear underbody air conditioning (AC) lines and their supporting structural mounting brackets have failed due to severe corrosion. Specifically, a heavy steel mounting bracket has rusted excessively, causing localized galvanic corrosion at the point of contact with the adjacent aluminum AC lines. This structural and material failure caused the aluminum line to erode, crack, and leak high-pressure chemical refrigerant into the environment. The vehicle, failed components, and detailed photographic evidence of the galvanic corrosion and rusted bracket are fully available for inspection upon request. 2. The failure presents multiple safety and health hazards: •Environmental and Inhalation Hazard: The high-pressure leak of mobile air conditioning refrigerant (R-1234yf or R-134a) releases a hazardous chemical compound directly beneath the cabin. •Defrost and Visibility Failure: The rapid loss of system pressure completely disables the vehicle’s climate control and window defrosting/demisting capabilities, severely compromising driver visibility during inclement or humid weather. •Structural Degradation: The severe rust and erosion of the underbody mounting bracket mean structural components are failing prematurely on a 2021 model, creating a risk of loose or dragging underbody debris at highway speeds. 3. The physical failure (loss of refrigerant and severe physical corrosion) has been visually confirmed. However, the Toyota dealership service center actively refused to document the cause. However, photographic evidence clearly reveals the distinct, localized galvanic corrosion occurring exactly where the rusted steel bracket contacts the aluminum line. Further, Toyota’s highlander model had this same problem which was addressed through T-SB-0021-26. 4. The vehicle was inspected by an authorized Toyota dealership which acknowledged the leak but refused to provide a written technical breakdown. 5. Rust, corrosion, and loss of cooling ability.

NHTSA ID

11745261

Incident

Jun 16, 2026

My 2021 Toyota Sienna Hybrid has an intermittent and dangerous brake failure where the brakes suddenly release pressure during normal braking. When slowing down—especially at lower speeds or approaching a stop—the brake pedal briefly loses resistance and the vehicle surges forward as if the brakes let go. I must immediately re‑apply hard pedal pressure to avoid rolling into traffic or another vehicle. The vehicle as a result can stop up to six feet past the intended stopping point in some instances. This issue is unpredictable and has occurred multiple times. It creates a serious safety risk. Toyota performed T‑SB‑0047‑24 (Brake ECU Reprogramming) on my vehicle, whereafter the brakes seemed to function normally for several months, but the problem resurfaced and occurred threee time in one week in May of 2026, which prompted me to bring it backk to Toyota for another look. The dealer has been unable to reproduce the issue and therefore has not repaired it. The veicle has been returned to me, and continues to have the problem intermittently at a random frequency. Toyota corporate Brand Engagement Center has been notified, and a case was opened (Ref # 260528002416). This case was closed however after telling me that the dealership connot reproduce the problem, therefore they cannot repair it. This appears to be a brake control defect involving the hybrid brake‑by‑wire system. Because the failure is intermittent and leaves no diagnostic codes, it is extremely difficult for the dealer to diagnose, but the safety risk is severe. I'd like to advise that I have owned and driven earlier hybrid models (2012-14) that never exhibited this type of brake failure. I'd also like to point out... an internet search of this problem reveals that this problem seems to be prevelant in newer Toyota hybrid models. This was confirmed by the service manager at my local dealership. I have not been informed of any continuing engineering efforts given the failure of the TSB.

NHTSA ID

11741894

Incident

May 27, 2026

SRS light has been showing up on the dashboard, off and on for 3 weeks. Diagnostic reader completed by the dealership states it is an airbag module malfunction of the 2nd row left passenger seat. The seat has never been removed, there have been zero accidents and no damage to the seat or wiring.

NHTSA ID

11740978

Incident

May 29, 2026

Although the HV Floor Under Wire Harness and Rear Traction Motor Cable is 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. Toyota is providing extended coverage under this Customer Support Program for repairs related to excessive corrosion to the wire harness connections at the Rear Motor Generator. Excessive corrosion can cause AM Radio Static during certain drive cycles, or the vehicle may not start.

OBSOLETE NOTICE February 27, 2026: This bulletin is no longer applicable and is now obsolete.

OBSOLETE NOTICE January 30, 2026: This bulletin is now obsolete. Please see T-SB-0001-26.

Some 2018 – 2024 model year Toyota vehicles equipped with a Premium Audio with Dynamic Navigation System require a Special Service Tool (SST) USB flash drive to update the map, points of interest, and system software.

Some 2005 – 2026 Toyota vehicles that have undergone water intrusion may exhibit a condition in which a musty odor is present. Follow the procedures in this bulletin to remediate the odor and address this condition. The purpose of this Service Bulletin is to provide general guidelines and procedures for odor remediation. This Service Bulletin provides a guide on how to prepare and treat the interior of the vehicle for odor remediation. Refer to the applicable model and model year Repair Manual and the EPA (Environmental Protection Agency) website for the most up-to-date safety and precautionary guidelines.

Although the HV Floor Under Wire Harness and Rear Traction Motor Cable is 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. Toyota is providing extended coverage under this Customer Support Program for repairs related to excessive corrosion to the wire harness connections at the Rear Motor Generator. Excessive corrosion can cause AM Radio Static during certain drive cycles, or the vehicle may not start.