2021 Toyota Sienna Hybrid Brakes Problems

This is a supplemental correction to my NHTSA complaint #XXX (2021 Toyota Sienna Hybrid, VIN [XXX]). The description of the brake defect itself is unchanged; I am correcting the service-history details. First dealer visit: the correct date is XXX, at approximately 41,192 miles, Repair Order #XXX, at Checkered Flag Toyota of [XXX]. I reported that when braking downhill, the vehicle seemed to speed up rather than slow down, as if something were pushing it forward. The service record states "No Work Performed – Customer Requested Return of Vehicle." No diagnosis or corrective action for the braking concern is documented. Second dealer visit: the visit spanned XXX, at approximately 55,637 miles, Repair Order #XXX, at the same dealership. I reported the vehicle lurching forward when attempting to stop and engine RPM increasing when the vehicle should have been slowing down. The technician's notes indicate the technician felt a small lurch when braking and noted an RPM abnormality — the concern was partially reproduced, not entirely unreproducible as my original complaint stated. The dealer reprogrammed the Brake ECU under Toyota TSB T-SB-0047-24. The problem returned a few months later and has continued intermittently since. I request that this correction be attached to complaint #11770036. INFORMATION REDACTED PURSUANT TO THE FREEDOM OF INFORMATION ACT (FOIA), 5 U.S.C. 552(B)(6)

NHTSA ID

11770245

Incident

Oct 7, 2026

I purchased my 2021 Toyota Sienna Hybrid new in March 2021. For several years I have had an intermittent braking problem: when I apply the brakes, especially while slowing down or driving downhill, the vehicle sometimes lurches or feels like it suddenly accelerates forward instead of slowing. I must press the brake pedal again to stop. This happens without warning and is frightening, especially with my children in the car. I first reported this to a Toyota dealer on 10/10/2023 at about 41,192 miles, and again on 7/11/2024 at about 55,637 miles. On the second visit the dealer reprogrammed the Brake ECU under TSB T-SB-0047-24. The technician could not reproduce my exact concern but said the bulletin described a similar condition. The problem has returned despite the update. Online owner forums show other Sienna owners with very similar braking complaints; some paid for repairs themselves, others sold their vehicles over safety concerns. I have seen claims that too few complaints have been filed to trigger a recall, though I cannot verify that. What concerns me is that Toyota issued a TSB for a similar condition, yet the problem persists. I have owned this vehicle since new and reported the problem multiple times. I have dealer service records from both 2023 and 2024. I ask NHTSA to investigate whether this is a widespread safety defect and whether a recall is needed before someone is seriously hurt.

NHTSA ID

11770036

Incident

Oct 7, 2026

brake sleeps sometime when i press brake pedal i took car to dealer once,they said need time i did not have much time took another time, they reseted system still... my warranty is over now. rear seat,make shake noise and check rear seat sign on dealer can't find problem. did not do anything since new car. i do not know any other 2021 sienna drivers have same problem.

NHTSA ID

11762371

Incident

Dec 31, 1969

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

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

The car jerks when coming to a stop. Like when the regenerative system is disengaged it jerks. For the Adaptive cruise control the car will accelerate instead of braking when another car merges in front of you.

NHTSA ID

11717402

Incident

Oct 16, 2025

The contact owns a 2021 Toyota Sienna Hybrid. The contact stated that while depressing the brake pedal, there was a three-second delay before the brakes would respond. Additionally, the brake pedal was difficult to depress, creating an extended stopping distance. The vehicle was taken to the local dealer who adjusted the brake stroke sensor and recalibrated the braking system; however, the failure persisted. The vehicle was later taken to a second dealer who bled the brake lines, but the failure persisted. The manufacturer was notified of the failure, but no assistance was offered. The failure mileage was 30,800. The VIN was not available.

NHTSA ID

11505111

Incident

Dec 1, 2022

Mileage

30,800 mi

THIRD BRAKE LIGHT CONDITION POOR VISABILITY TO OPERATOR ( REAR WINDOW) WHEN BRAKE IS ACTIVATED IN LOW OR DARK LIGHTING CONDITION(S) THERE IS REFLECTION OFF GLASS AND REAR DEFROST ELEMENT(S) WHICH CAUSE LIMITED REAR VISABILITY OUT OF REAR WINDOW GLASS.

NHTSA ID

11377621

Incident

Nov 25, 2020