2021 Toyota REDUNDANT SIENNA problems and owner complaints
Explore the records behind recurring owner reports.
Key facts
165 owner complaints analyzed
1 distinct recall campaigns
28,000 mi median reported failure mileage
Scope: 2021 model year. Data snapshot: . 11 complaints include usable failure mileage.
Most common problems
Service Brakes is the most frequently named component, appearing in 80 of 165 complaints (48.5%). A complaint can name multiple components.
| Topic | Matching reports | Share of complaints |
|---|---|---|
| Braking behavior | 73 | 44.2% |
| Electrical and battery issues | 11 | 6.7% |
| Transmission and shifting | 3 | 1.8% |
| Steering behavior | 3 | 1.8% |
| Engine operation | 2 | 1.2% |
| Fuel system concerns | 1 | 0.6% |
Topic matches use published keyword rules. They describe mentions, including negations or comparisons, and do not confirm a diagnosis. Read the matching rules.
Component breakdown
Number of unique complaints naming each component. Top eight shown.
| Category | Count |
|---|---|
| Service Brakes | 80 |
| Unknown Or Other | 27 |
| Seats | 17 |
| Air Bags | 16 |
| Electrical System | 13 |
| Vehicle Speed Control | 9 |
| Engine | 8 |
| Power Train | 8 |
Service Brakes: 80; Unknown Or Other: 27; Seats: 17; Air Bags: 16; Electrical System: 13; Vehicle Speed Control: 9; Engine: 8; Power Train: 8
Reported problems by failure mileage
Complaint counts in mileage bands. These are not failure rates per vehicle or mile.
| Category | Count |
|---|---|
| Under 25,000 | 5 |
| 25,000 to 49,999 | 4 |
| 50,000 to 74,999 | 1 |
| 75,000 to 99,999 | 1 |
| 100,000 to 149,999 | 0 |
| 150,000 and above | 0 |
Under 25,000: 5; 25,000 to 49,999: 4; 50,000 to 74,999: 1; 75,000 to 99,999: 1; 100,000 to 149,999: 0; 150,000 and above: 0
Under 25,000 miles has the most reports with usable mileage (5). 154 complaints have missing, zero or invalid mileage.
Complaints over time
Year the complaint was filed, not the vehicle model year or incident year. The snapshot year is partial.
| Category | Count |
|---|---|
| 2021 | 17 |
| 2022 | 37 |
| 2023 | 34 |
| 2024 | 46 |
| 2025 | 26 |
| 2026 | 5 |
2021: 17; 2022: 37; 2023: 34; 2024: 46; 2025: 26; 2026: 5
Pattern summary
Service Brakes leads the component reports. Braking behavior appears in 73 complaint narratives. Electrical and battery issues appears in 11 complaint narratives. Transmission and shifting appears in 3 complaint narratives. Use these patterns to inspect individual reports and prepare questions for a mechanic.
Calculated from recorded counts. An AI narrative has not been published for this selection.
Complaint evidence
Examples provide context, not a representative sample or a verified diagnosis.
Owner report 11423107 · 2021-07-01 (July 1, 2021)
Van has just over 5k miles. Multiple warnings occurred while at speed on a highway. Primary warning was 'Low Brake Power' and braking became extremely touchy as it seemed to utilize the emergency brake as a backup. This extreme braking is hazardous and could result in an accident caused by braking too quickly - with a possible rear-end collision by traffic to the rear. Additional warnings/malfunctions were listed as well, due to the low brake power: LTA Malfunction (Lane keep assist), Automatic Emergency Brake Malfunction, Parking Brake Malfunc…
Owner-reported narrative. Look up ODI 11423107 at NHTSA ↗
Owner report 11426402 · 2021-07-26 (July 26, 2021)
We were driving down the freeway when we got rear ended hard by a large pickup. Then we lost electrical and engine power. The brakes stopped working. The hazard lights stopped working. Luckily we were able to coast to a complete stop as there was no way to stop the car. The police came and took a report. Then the car was towed to a body shop. We're awaiting the insurance company adjuster for inspection.
Owner-reported narrative. Look up ODI 11426402 at NHTSA ↗
Owner report 11455682 · 2022-03-08 (March 8, 2022)
While driving during snowy weather suddenly smoke began to billow from steering column area and vehicle slowed down, then stopped, while simultaneously several malfunction indicators lit, I tried to restart the vehicle to pull to a berm, it was unable to restart or even shift into neutral, the vehicle lost all power and had to be towed. This alone could have caused an injury or accident. The problem was from an electrical short from a hole in the firewall made by VMI which permitted snow, road water, and road salt to enter into the cabin area o…
Owner-reported narrative. Look up ODI 11455682 at NHTSA ↗
Owner report 11675599 · 2025-07-23 (July 23, 2025)
sound coming from engine / transmission other issues with the 2 ruber seals on the minivan keep worping out i looked on all the forms everyone is making the same complaint i toook it to toyota they just put tape and its off again they didnt help for a perminent fix back door is miss alined pasanger side sliding door sometimes does not close takes 3-4 atempts pressing the button
Owner-reported narrative. Look up ODI 11675599 at NHTSA ↗
Owner report 11523611 · 2023-05-24 (May 24, 2023)
The vehicle has had rocks get in the suspension 4 times so far which creates loud clunking noises and can cause a noticeable feel in the steering. The most recent time, after the rock entered the front end, the brakes were soft and required excessive pedal force followed by a clunk before the brakes abruptly applied. I like on a paved road with a rock driveway and it seems like the shielding for the front end is inadequate. I have friends with a 2022 sienna that live on a gravel road that have experienced similar issues.
Owner-reported narrative. Look up ODI 11523611 at NHTSA ↗
Owner report 11582842 · 2024-04-14 (April 14, 2024)
This incident had happened twice in the last 30 days. I have been stopped, then starting to accelerate after a stop sign, I push on the accelerator and the vehicle slows down, as if it’s losing power for about 5 seconds. I do not release the accelerator and after the 5 seconds of what feels like no power, the van begins to accelerate like normal. This poses a severe safety risk while crossing intersections when you believe your vehicle should respond when pushing on the accelerator. I did not have any notifications pop up on my van, I was in …
Owner-reported narrative. Look up ODI 11582842 at NHTSA ↗
Owner report 11687704 · 2025-09-16 (September 16, 2025)
While driving my 2021 Toyota Sienna Hybrid, the vehicle suddenly displayed a low oil pressure warning, immediately lost power, and entered limp mode. I was able to pull over safely, but the engine then suffered a catastrophic failure , a connecting rod blew through the engine block, leaving large metal fragments inside the engine compartment. The vehicle is completely inoperable. Prior to this event the van sometimes idled rough and shook slightly on startup when transitioning from battery to gasoline engine after sitting, but it drove normall…
Owner-reported narrative. Look up ODI 11687704 at NHTSA ↗
Owner report 11535892 · 2023-08-01 (August 1, 2023)
The contact owns a 2021 Toyota Sienna. The contact stated that while his wife was fueling the vehicle, his 5-year-old son pressed the automatic rear driver's side sliding door switch and the door opened, bumped, and scraped the fuel door. The contact's wife immediately stopped fueling the vehicle. The contact stated that the vehicle was designed with an automatic door lock that should engage to prevent the rear driver's side sliding door from opening and bumping into the fuel door while fueling the vehicle; however, the automatic door lock fail…
Owner-reported narrative. 49,000 miles reported. Look up ODI 11535892 at NHTSA ↗