2021 Toyota Sienna Hybrid Problems

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.

Unknown, I got the SRS Airbag system malfunction in my vehicle, I got the same error in my vehicle dashboard a few times in the past but it would go away and since yesterday I have the message in my dashboard

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.

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.

The contact owns a 2021 Toyota Sienna Hybrid. The contact stated that the passenger's side rearview mirror detached and the rear liftgate door inadvertently opened while parked in the garage. The vehicle was taken to the dealer but was not yet diagnosed nor repaired. The manufacturer was not made aware of the failure. The failure mileage was approximately 9,000. The VIN was unavailable.

THE 2021 SIENNA XLE PLUS AND ENTERTAINMENT PACKAGE DID NOT INCLUDE A DIGITAL REAR VIEW MIRROR IN THIS TRIM LEVEL. THE NEW SIENNA IS A BRAND NEW MODEL WITH A MASSIVE DESIGN FLAW, A HUGE TV WITH ZERO VISIBILITY OUT THE REAR OF CAR. IT'S UNSAFE. MANY PEOPLE WILL NOT TEST DRIVE WITH THE TV DOWN TO SEE THE SAFETY ISSUE. WE DIDN'T REALIZE IT TILL KIDS PUT THE TV DOWN DAY LATER. SEEMS TO HAVE SADLY MADE IT THROUGH QUALITY CONTROL PROCESS AT TOYOTA. YOU CAN NOT SEE CARS RIGHT UP ON YOU AT STOP SIGNS, CARS APPROACHING ETC IT NEEDS A SAFETY RECALL AND A MODIFICATION.WE HAVE HAD CAR FOR 3 WEEKS.

The contact owns a 2021 Toyota Sienna Hybrid. The contact stated that while the vehicle was parked, the contact observed a melted spot, almost identical on the driver’s and front passenger’s lower back rest on the seats. The vehicle was not diagnosed or repaired. The manufacturer was notified of the failure. The failure mileage was approximately 60,000.

The contact owns a 2021 Toyota Sienna Hybrid. The contact stated that while driving at an undisclosed speed, there was an abnormal rattling sound coming from the second-row seats. The message to "Check Rear Seats" was displayed. No warning lights were illuminated. The vehicle was not taken to the dealer or an independent mechanic. The vehicle was not repaired. After investigating the failure, the contact related the failure to NHTSA Campaign Number: 25V086000 (Seats); the VIN was included, and the vehicle was repaired. However, the contact was informed that the remedy was for the third-row seat only. The manufacturer was notified of the failure, a case was opened, and the contact was referred to the NHTSA Hotline to report the failure. The failure mileage was 169,000.

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)

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.

We were stopped at a stoplight. As soon as we stepped on the gas pedal, there was a loud clunk sound and plastic parts started flying out from under the car. We immediately pulled over. Oil was spilling out everywhere. The transmission oil pump was laying on the inside of the engine compartment. We had towed to Toyota. They diagnosed a bent piston went through engine which also caused a hole in the transmission. I had it towed for a 2nd opinion. Neither toyota or the 2nd opinion had ever seen anything like it. My mechanic also said there are a bunch of other suspension parts that were damaged due to the violent stop of the engine. There are a few of the same incidents online in chat rooms. The car is totalled and we are out of a car now.

The contact owned a 2021 Toyota Sienna Hybrid. The vehicle was parked in the driveway when an explosion occurred; the vehicle burned down. The contact was inside the residence when a loud noise was heard, and the house "rocked." The contact ran to the front of the house to investigate and noticed that the vehicle was engulfed in flames. The fire damaged the driveway, melted the garage door, and melted a landscaping retaining wall. The fire damaged the post on the front porch. The contact and her family were unable to exit through the front door due to the fire and used the sliding kitchen door to exit the residence. The fire department was called to the scene. Per the contact, three fire trucks were at the scene. The fire department informed the contact that the fire went up to 3,000 degrees. The fire department concluded that the fire started from underneath the driver's back panel. The contact stated that the gas tank was underneath that area and believed the gas tank may have contributed to the fire. The towing company towed the vehicle to a towing yard, and it was later picked up and towed to an unknown location. The insurance company was notified and declared the vehicle a total loss. The manufacturer was made aware of the failure and advised the contact that an inspection was needed on the vehicle and asked for the location of the vehicle.  However, the contact was awaiting the results. The failure mileage was approximately 80,000.

The contact owns a 2021 Toyota Sienna Hybrid. The contact stated that while driving at an undisclosed speed, the contact heard an abnormal splashing sound inside the vehicle. The contact stated that while the vehicle was parked, there was water coming from underneath the doors. The vehicle was not diagnosed or repaired by an independent mechanic or the dealer. The contact related the failure to Technical Service Bulletin: 0121-20 (Sloshing or Splashing Noise Caused by Water Inside Doors); however, the vehicle was not covered under the TSB. The manufacturer was made aware of the failure but provided no assistance. The failure mileage was approximately 22,500.

The contact owns a 2021 Toyota Sienna Hybrid. The contact stated that after pressing the rear lift gate button, the rear liftgate door failed to open, trapping the dog inside the vehicle. The contact stated that the rear liftgate door was later manually forced open by two good Samaritans and the dog was retrieved. The vehicle was later taken to the local dealer who diagnosed that the failure was caused by a faulty passenger’s side liftgate strut bolt. The liftgate strut and bolt were replaced and the vehicle was repaired. The manufacturer was notified of the failure. The failure mileage was 67,000.

HEADLINER CUT TOO LARGE, DOESN'T HOLD REAR PASSENGER CLIMATE CONTROLS, CLIMATE CONTROLS FALL OUT AND HIT REAR PASSENGERS. THIS HAPPENS AT ANY SPEED.

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.

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)

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.

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.

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.

Both front struts of the vehicle have failed and are leaking. There is only 36,000 miles on this vehicle when they should last 200,000 miles per Toyota's service department. Toyota refuses to acknowledge this is their problem and that it's a "wear and tear' part. However clearly these parts should not fail after so little usage.

We were stopped at a stoplight. As soon as we stepped on the gas pedal, there was a loud clunk sound and plastic parts started flying out from under the car. We immediately pulled over. Oil was spilling out everywhere. The transmission oil pump was laying on the inside of the engine compartment. We had towed to Toyota. They diagnosed a bent piston went through engine which also caused a hole in the transmission. I had it towed for a 2nd opinion. Neither toyota or the 2nd opinion had ever seen anything like it. My mechanic also said there are a bunch of other suspension parts that were damaged due to the violent stop of the engine. There are a few of the same incidents online in chat rooms. The car is totalled and we are out of a car now.

The contact owns a 2021 Toyota Sienna equipped with Cooper Tires, Tire Line: Discoverer True North, Tire Size: 235/35/R17, DOT Number: RN811KW1322. The contact stated while his wife was driving approximately 65 MPH, the front driver's side tire sustained a blowout. Upon inspection, it was discovered that the sidewall of the tire had failed. The cause of the failure was not yet determined. The contact stated that prior to the failure, the tire was taken to the local dealer regarding slight bulging on the sidewalls, but the contact was informed that the tires were safe for driving. The manufacturer was not contacted. The failure mileage was 37,000.

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.