2017 Toyota Sienna: sudden loss of power

Filed Jul 11, 2026 · Transmission · CA

I, as well as other owners of 2017–2018 Toyota Highlanders and 2017–2018 Siennas are experiencing serious transmission issues—including high-pitched whining, erratic shifting, clunks, hesitation, and premature failure. My 2017 Toyota Sienna has the UA80 8-speed automatic transmission at issue and started whining upon acceleration in March/April 2026 timeframe. It has always had the clunking and hesitation problem. According to Gears Magazine, the issue stems from a flawed assembly process involving the counter drive gear support. A locking tab meant to secure a vital retaining nut was not bent properly during factory assembly. This leads to gear movement, internal wear, whining, and eventually failure. Unknown to me, in 2019, Toyota had acknowledged the problem in Technical Service Bulletins T-SB-0160-18, T-SB-0008-21, which only go to dealers, and implemented a limited Customer Support Program (CSP ZJC)—but only offered coverage to a narrow group of VINs, not to all VINs for model years that have these transmissions. My car is experiencing these same symptoms. My Toyota Dealer confirmed this problem and recommended a transmission replacement for $11,000 including labor. They said my VIN was not included in the Customer Support Program. Driving with a failing transmission is highly dangerous. A bad transmission can cause sudden power loss causing the car to halt to a sudden stop, unintended acceleration, or my car might get stuck in neutral while driving. I could lose control or be unable to get to the shoulder on the highway, cause a rear-end collision, or get stuck in busy traffic. DESIRED OUTCOME REQUEST: My VIN should be covered under the Customer Support Program in the category of cars that are “less than 10 years old regardless of mileage” or a full recall of all VINs of these model years with these transmissions should be executed. Thank you.

Filed Jun 22, 2026 · Fuel system · FL

While driving at speed, the vehicle suffered a sudden and complete loss of engine power and stalled in traffic. The vehicle was diagnosed by an independent mechanic who found a failed factory-installed Denso fuel pump module. This failure mirrors Toyota Safety Recall 20TA02 (the federal safety agency Campaign 20V012) for the exact same model year 2017 Toyota Sienna, but my specific VIN is currently excluded from the recall list. The un-recalled defective component created an immediate highway safety hazard as me and my family were left stranded in the middle of the road. We waited for hours at the risk of oncoming traffic until we were able to have a tow truck lift the van and take to the nearest repair facility (an independent service center - Goodyear Auto Service). The repair facility diagnosed the problem and confirmed that the fuel pump failed to generate enough pressure causing the vehicle to stall and not start again. To correct the problem, the fuel pump was replaced with an OEM toyota fuel pump module assembly.

Filed Apr 17, 2026 · Transmission · TX

Loss of power highway speeds, jerky shifting, “sealed” transmission leaking fluid. Check engine light and service required light. I have noticed poor performance with this vehicle before and reported it to the dealer to no avail. Toyota has enacted “customer support program ZJC” but the dealership will not honor.

Filed Jan 20, 2026 · Transmission · 120,000 miles · CO

The contact owns a 2017 Toyota Sienna. The contact stated that while starting the vehicle, reversing, and then while driving 20 MPH, there was an abnormal whining sound coming from the front of the vehicle. A dealer was contacted. The vehicle was taken to the dealer and was currently being diagnosed. The vehicle was not repaired. The contact related the failure to Technical Service Bulletin: TSB-0160-18 (Transaxle Whine Noise, Harsh Shift, MIL ON, or Reduced Power); however, the VIN was not included in the bulletin. The manufacturer was notified of the failure and referred the contact to the federal safety agency Hotline to report the failure. The failure mileage was 120,000.

Filed May 22, 2022 · Electrical, Engine · WI · fire

I was driving my 2017 Sienna on 5/10/2022 and was approaching a roundabout. As I was going thru the roundabout, my van stalled. I coasted into a gas station. After a few minutes I notice smoke coming from under my hood. I popped the hood and noticed the smoke was coming from the air intake. We called AAA and they towed it to the dealership we bought it new from and had all services done at. The next day we authorized them to do a diognostic on it where they found a burnt airfilter and melted housing. Heiser Toyota in Milwaukee WI has not repaired the van yet and we wanted to talk to Toyota customer service and your office to see what we should do. We called insurance and a claim has been started - not sure if they have inspected the van yet. It is available for you to inspect. All warning lights were on when it stalled. There was no power loss or any warning before it stalled.

Filed Jul 30, 2018 · Transmission · 5,900 miles · MD

July 22 2018 afternoon. I was driving the sienna 2017 on a highway in speed 70mph in the ect mode with my wife and kids. It seemed everything normal at the beginning. When I was pressing gas pedal the car did not accelerate at all. On the contrary, the mini-van was slowing down. I became nervous since that was a 3 lanes highway, I was in leftist lane and there was narrow cube and did not have enough space to stop. I pressed gas pedal harder, and engine got to 6000 RPM however there was no power at all. What made me more nervous was that the display did not show the transmission indicator at all. The display supposes always show the transmission indicator such as p/n/d'. However, at that time the display did not show any of that, the display area was blank. I also pulled the shift handler backward to make sure the gear was on 'd' , instead of 'n'. That did not help. I asked my wife to turn on the emergency light since I had to focus to control the car. I was doing pressed/release gas paddle repeat and it provided a little bit power to the car. I managed switched to the rightest lanes and get to a closed exit. I stopped the car, opened the front hook and saw nothing wrong. Once I restart the minivan, I saw the 'p' showed up in the display. I tested the mini van. Seemed to me, it was back to normal. I drove with extra caution and fear back to home. All this happened right after the very first 5000 miles service for my new car. Transmission lost power in the highway is very dangerous. It may cause fatal accident. I am worried this may happy again in the future. I am scared to drive this car in a highway with my family. I request this to be investigated to prevent it from happening again.

Filed Jul 1, 2018 · Body, Engine · 13,700 miles · KS · fire

I was driving on the interstate at approximately 65 miles per hour. My 'check all wheel drive system' warning alarm came on shortly followed by the: check engine, battery alarm, collision breaking system, etc. I'm certain there were more alerts going off; however I was trying to steer a car, that had lost power off the roadway. I was able to get the car safely onto the shoulder where I attempted to turn off the vehicle. I couldn't turn the car off until I realized I needed the car to be in park. After I turned the car off I noticed black smoke coming from the engine and could smell something burning. I opened the door & got my three year old son out of the car & noticed more black smoke. I quickly distanced myself from the vehicle & noticed fire coming from the engine. I called 911 but the car was engulfed in flames within minutes. The fire department responded within 5 minutes & were able to extinguish the fire.