2020 Toyota Sienna — Known Issues & Recalls

Your transmission suddenly failed completely while driving downhill at 85,000 miles with no warning signs, check engine lights, or overheating beforehand. This sudden loss of power created a serious safety risk for you, your passengers, and other vehicles on the road. The transmission assembly will need to be replaced by a dealer.

Your car stopped shifting gears properly and experienced sudden, unpredictable acceleration that made it dangerous to drive. The transmission contained broken metal pieces inside, and the check engine light came on. Your dealer determined the transmission had failed after only 70,900 miles at just 3 years old. The transmission will likely need to be rebuilt or replaced.

Your transmission is making a whining noise that has developed over five years of ownership. Your dealer says the transmission needs to be replaced, though a second opinion suggests this noise isn't normal. While it's currently just a sound, you're concerned it could fail unexpectedly, which is especially important given your need for reliable transportation with a wheelchair-accessible vehicle. Fixing this will likely require transmission repair or replacement by a qualified mechanic.

Your driver's side power sliding door became stuck and wouldn't open, even after disabling the power door system. The cable for the power mechanism was bound up inside the door assembly. You were able to manually force the door open and cut the stuck cable, allowing the door to operate as a manual slide instead. The owner believes this design flaw affected 2019-2020 models and should have been recalled, since a similar issue was documented before these model years were built.

Your passenger side rear door unlocked and opened by itself in the middle of the night without any warning. The doors were locked before this happened, and it wasn't caused by accidentally pressing a key. This suggests a potential issue with the door locking mechanism or electrical system that controls the locks.

Your fuel door hinge is rusting and breaking, which is preventing your rear passenger door from opening automatically. The hinge appears to be poorly constructed and not durable enough to withstand normal use. Fixing this will likely involve replacing the fuel door hinge and possibly adjusting or replacing the door latch mechanism.

Your pre-collision system, lane assist, and airbag warning lights came on while driving. The dealer replaced a fuse in the engine control unit, but the problem came back 10 days later. The dealer then determined the wiring harness needs to be replaced, but it was on backorder and your vehicle wasn't repaired. This happened at around 60,000 miles.

Your car is experiencing multiple random electrical issues: turn signals activate on their own, the radio volume changes unexpectedly, the CarPlay USB connection drops and reconnects repeatedly, and the engine hesitates during acceleration when ECO mode engages. These symptoms suggest an underlying electrical or computer system problem. The issues may require diagnostic testing to identify the root cause, which could involve replacing a faulty control module, fixing wiring connections, or updating software.

Your car's speakers occasionally emit a sudden, extremely loud piercing noise that lasts about a second. This happens randomly and hasn't been reproduced at the dealership, with no warning signs beforehand. The noise could distract you while driving or potentially harm passengers' hearing, especially children. The fix will likely involve diagnosing the audio system for electrical faults or speaker defects and replacing or repairing the faulty components.

Your sunroof is leaking or clogged, allowing water to enter the interior of your vehicle. This water intrusion has caused extensive damage and is affecting various vehicle systems. The issue likely requires cleaning or repairing the sunroof's drainage system and addressing any resulting water damage inside the cabin.

You may have purchased a vehicle with a tampered odometer. The seller's van showed 77,000 miles on both the odometer and in the sales listing, but the California DMV title showed 143,000 miles. The seller admitted to replacing the dashboard, which suggests the odometer reading was altered to show lower mileage than actual. This is odometer fraud, and you may want to report it to authorities and verify the vehicle's actual mileage through DMV records.

The jack that came with your vehicle failed while you were using it to change a tire. This is a safety concern since a failing jack could cause the vehicle to drop unexpectedly. You should have the jack inspected or replaced before attempting any tire changes.

While driving at various speeds, your power steering suddenly stopped working, and your dashboard displayed warning messages about the Vehicle Stability Control System, Pre-Collision System, and Lane Departure Alert all malfunctioning at the same time. Even after an independent mechanic replaced the rack and pinion, the power steering failure returned. This issue matches a known Toyota steering recall (Campaign 19V532000), but your dealer said there were no open recalls on your vehicle.

Your car's brakes may have failed while turning at low speed, causing the vehicle to skid and triggering the ABS warning light. A dealer diagnosed a faulty speed sensor on the front passenger side and a cracked brake actuator as the cause. Fixing this will likely require replacing the speed sensor and brake actuator assembly.

Your driver's side rear view mirror came loose from its housing in August 2024 and is now only held in place by the wiring for mirror controls and defrost. You've had to duct tape it repeatedly to keep it stable, and both dealers told you the mirror must be replaced rather than repaired — with quotes around $2,000. The replacement mirror has been on national backorder for months despite repeated promises from Toyota and dealers that it would arrive within weeks, leaving your car potentially unsafe to drive and unable to pass inspection.

Your brake pedal is unusually small—less than 4 inches wide—making it difficult to locate quickly with your foot while driving. You may lose a second or two searching for it, which feels dangerous, especially compared to other vehicles you've owned with much larger brake pedals. Addressing this would likely require replacing the brake pedal assembly with a larger design.

Your van has experienced multiple episodes of shuddering at startup with the RPM gauge jumping, along with hard acceleration and jerking. Most concerning, the Traction Control System has turned off twice after refueling, accompanied by a check engine light and a message about an engine control malfunction, leaving the van barely able to accelerate. Toyota's service department cleaned your fuel injection system and flushed the fuel ($725), but the problem recurred after refueling at different gas stations, though the dealer later reported they couldn't detect any issues. The fix likely involves further fuel system diagnostics, possible fuel filter replacement, or evaluation of the engine control sensors.

Your Sienna has been hesitating and idling roughly, with RPMs revving while parked. On one occasion, the van was shaking badly, wouldn't accelerate, and became undrivable. Even after a $725 gas tank flush and fuel injector cleaning at a Toyota dealership, the rough idling and hesitation have persisted. The issue may require further fuel system diagnostics or component replacement.

Your vehicle stalled while driving at highway speeds (60-65 MPH) with warning lights appearing on the dashboard. You were able to restart it and continue driving. The dealer replaced your fuel pump under a recall, but about a year later the same stalling problem happened again. The dealer couldn't reproduce the issue during testing, so no repair was made. The fix may require additional fuel system diagnostics or a replacement fuel pump assembly if the original part is defective.

Your engine stalled while idling at a red light in traffic with no warning lights, but restarted normally. Later that same day, the engine stumbled and hesitated for a few minutes after starting. The problem happened again on a different occasion when accelerating from a stop—the engine briefly died, the master warning light came on, all power cut out, but it recovered when you gave it more throttle. The dealer found no issues when they checked it after the first incident.