2018 Toyota Sienna: hesitation when accelerating

Filed Nov 6, 2026 · Transmission · AZ

Since 2018–2019, our 2018 Toyota Sienna has had recurring drivability and suspected transmission problems, including stalling, failure to engage or accelerate when the accelerator is pressed, rough idle, hesitation, and harsh shifting. We reported these concerns to Toyota and filed an the federal safety agency complaint during our first year of ownership. The problems have continued intermittently for years and now include transmission whining, slipping, delayed gear engagement, irregular shifting, and reduced power. Unexpected stalling or failure to accelerate creates a safety risk when entering traffic, crossing intersections, or avoiding hazards. On October 19, 2026, AAA inspected the vehicle following a four-wheel-drive malfunction warning. Its October 20 invoice documents UA80F eight-speed transmission-related fault codes P0740-7E, P2713-7F, and P2756-7F and notes possible sticking valve-body solenoids. Toyota's own Technical Service Bulletin T-SB-0160-18 (issued December 17, 2018; revised May 11, 2021), titled "Transaxle Whine Noise, Harsh Shift, MIL ON, or Reduced Power," applies to certain 2017–2018 Siennas and lists these exact three codes (formatted P07407E, P27137F, P27567F). Toyota's Customer Support Program ZJC, Policy Bulletin POL19-04 (2019), also acknowledges transmission whine, harsh shifting, reduced power, and warning lights in certain UA80-equipped vehicles and describes a possible assembly defect involving a washer tab and loosening internal nut. An authorized Toyota dealer evaluated the vehicle October 24–30, 2026, after receiving AAA's findings but reported it could not reproduce a warning light and that the VIN/transmission serial number were outside program limits. No transmission repair was performed. The vehicle remains unrepaired. Please investigate whether this longstanding safety-related failure affects vehicles beyond Toyota's stated production cutoff.

Filed Jun 21, 2026 · Transmission · CA

Since owning my 2018 Toyota Sienna, I have experienced hesitation and erratic shifting with my transmission. I have the UA80E transmission which upon research others are experiencing issues with as well. It appears Toyota is not fully acknowledging the problem. The problem is a safety issue as sometimes when you go to quickly accelerate (merging, making a turn while starting from a stop, etc) the transmission hesitates and doesn't engage for a few seconds. This is an ongoing problem with the transmission. Toyota really needs to fix these transmissions!

Filed Feb 2, 2026 · Transmission · 126,000 miles · SD

The contact owns a 2018 Toyota Sienna. The contact stated that while driving 30 MPH and ascending a hill, the vehicle started making an abnormal whining sound and hesitated while accelerating. The vehicle was driven to the dealer to be diagnosed. The vehicle was diagnosed with transmission failure. The manufacturer was notified of the failure. The failure mileage was approximately 126,000.

Filed Aug 4, 2025 · Transmission · WA

Transmission Whine and Hesitation. Low gear it will hesitate from stop. Know issue with this transmission. There should be a recall on all ua80 transmissions.

Filed Jan 22, 2024 · Fuel system · KS

When accelerating, both from a stop and/or at speed, there is a definite hesitation. When gas pedal is pressed down, there is a noticeable pause before acceleration begins. This causes safety issues especially when accelerating to merge with moving traffic. Have owned this van since Oct 2021, and it has always been an issue. Possible fuel filter problem. Have not reported issue to dealer. Currently under extended warranty.

Filed Mar 24, 2023 · Transmission · 132,000 miles · CA

The contact owns a 2018 Toyota Sienna. The contact stated while driving at an undisclosed speed, the vehicle hesitated while accelerating. Several unknown warning lights were illuminated. Additionally, the "Pull Over - Take to Dealer" message was displayed. The vehicle was taken to the dealer, where it was determined that the transmission needed to be replaced. The vehicle was not repaired. The manufacturer was made aware of the failure and confirmed that the VIN was not included in Customer Support Program: ZJC (Coverage for UA80 Transmission). The failure mileage was approximately 132,000.

Filed Mar 5, 2020 · Fuel system · 35,000 miles · FL

Tl* the contact owns a 2018 toyota sienna. The contact stated that after coming to a complete stop, the vehicle hesitated without warning as the accelerator pedal was depressed. Upon investigation, the contact discovered the federal safety agency campaign number: 20v012000 (fuel system, gasoline) however, the parts to do the repair were unavailable. The contact stated that the manufacturer exceeded a reasonable amount of time for the recall repair. Neither the dealer nor the manufacturer was notified of the failure. The failure mileage was 35,000. Vin tool confirms parts not available.