Electrical, suspension and steering issues among the top complaints received by the NHTSA from vehicle owners
Driving a minivan might not seem cool these days but Toyota aims to appeal to a larger crowd with the 2020 Sienna. The automaker claims it is “the one and only swagger wagon.” But owners whose vehicles stall, shake, lose power, and/or won’t accelerate aren’t swaggering!
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Multiple complaints to the National Highway Traffic Safety Administration (NHTSA) show that there are major issues with the 2020 Toyota Sienna. In terms of complaint numbers, consumers believe that the fuel system, engine, powertrain, and electrical system are to blame for most of their problems. However, across the board, complaints talk about vehicles shaking, stalling, and failing to accelerate, blaming different components and systems for their problems.
Other components and systems that owners believe are causing problems include the electronic stability control system, seats, steering, structure, and wheels of the car.
There are also two recalls, one due to a fuel system problem and the other because of a major steering issue.
The first recall, issued in July 2019, only affected 595 Toyota Sienna 2017-2020 vehicles. It was prompted by the fact that the steering shaft extensions may have been improperly manufactured, possibly causing the extensions to fracture. If this happens it can cause a total loss of steering, which inevitably increases the risk of the Sienna crashing. In this case, dealers were to replace the steering shaft extensions, free of charge.
The NHTSA records don’t indicate that the recall was closed, but one alarming complaint that was filed with the NHTSA in September 2022 indicates that it was. The owner of a 2020 Sienna states that “while driving at various speeds, the vehicle lost power steering assist. Additionally, the ‘Check Vehicle Stability Control System’, ‘Pre-Collision System Malfunction’, and ‘Lane Departure Alert’ messages were displayed.” The rack and pinion were replaced by an independent mechanic, but the failure persisted. The owner then went back to the dealer who said there were no open recalls on the VIN. Months later, the owner linked the failure to the recall! At that stage, the Sienna had not been repaired.
The second recall, issued in November 2020, was for 1,525,742 Toyota vehicles — and not just Siennas. This warns that the low-pressure fuel pump inside the fuel tank may fail. If this happens, the engine can stall while driving, increasing the risk of a crash.
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| Complaint Category | Number of Complaints |
|---|---|
| Electrical System | |
| Engine | |
| Fuel/propulsion System | |
| Power Train | |
| Unknown Or Other | |
| Steering | |
| Fuel System, Gasoline | |
| Service Brakes | |
| Structure:body | |
| Electronic Stability Control (esc) |
The first NHTSA fuel-related complaint stated that the vehicle intermittently jerked and lunged forward at various speeds when the accelerator pedal was depressed. There was never a warning. It later emerged that this 2020 Sienna was included in the July 2019 recall, NHTSA Campaign Number 20V682000, mentioned above. At the time — more than a year after the recall had been announced — the parts to repair the problem were still not available!
Another owner whose Sienna was included in the recall reported to the NHTSA in May 2022 that his vehicle was repaired but the failure recurred a year later. Because the dealer’s mechanic was unable to duplicate the failure, it wasn’t repaired a second time.
An owner from Florida experienced a drastic loss in power and all warning lights illuminated. This happened after the fuel pump recall repair! The complaint states that the vehicle “had been functioning perfectly up until this massive failure. When (the) tow truck operator arrived and tried to start, it caught fire and was severely damaged.”
There are also several complaints that state dealerships charged them “to flush the gas” after they had problems with their fuel systems. This was supposed to clean the fuel injection system. For instance, an owner from Texas states that the van had been hesitating periodically, idling roughly, and when parked, the RPM would rev. When the van “was shaking, hesitating, and would not accelerate,” it had to be towed. The Toyota dealership “charged us $725 to flush the gas and clean the fuel injection system. Despite this, it is still hard-idling and hesitating.”
Loss of acceleration is a common complaint that owners relate to engine problems. But there aren’t any obvious solutions. An owner from Texas states that the engine light suddenly came on while driving down the highway. When he pressed the gas pedal there was no response from the car. Because the van was slowing down, he pulled into a gas station.”When I stopped the car, (the) engine light was still on. The traction light came on and (the) steering system light came on. Also (the) engine light was solid and it was not flashing.”
An owner from Arizona tells how the engine of his 2020 Sienna stalled in heavy traffic after stopping at a red light. It started after he turned the engine off. It started normally again, but then “stumbled on and off for the next few minutes but did not die.” The master warning light lit up briefly before the vehicle lost all power. The dealer could find nothing wrong!
An owner from Tennessee states that his 2020 Sienna with 16,000 miles would accelerate slowly from a stop, hesitate, shake, and then run “rough as it slowly progresses through first, second, and third gears.” When it gets into fourth gear the “hesitation and roughness goes away. This issue is rapidly getting worse.”
Illustrating how complaints are inter-connected, the first complaint about the Sienna’s powertrain states that after it had a post-purchase service, the dealership was advised by the automotive technician that there was a mechanical problem. A hose had come loose in the axle of a Texas owner’s vehicle and fluid was leaking out. It emerged that the axle was “coming apart internally.” It was replaced under warranty.
Another owner from Texas states that there were “intermittent incidents of the van shuddering and the RPM needle jumping upon ignition. Sometimes the van would have a hard time accelerating before jerking and driving normally.” This problem was also identified as a “bad gas” and the owner was charged for the fuel injection system to be flushed and cleaned. That worked for a while until he got this message: “A malfunction in the electronic control of the engine, throttle, or automatic transmission has been detected.” He had the van towed to a dealership — but two days later they said they couldn’t detect any issues!
If you think that your 2020 Toyota Sienna may be a lemon, Lemberg Law may be able to help you. Automakers are frequently forced to buy back, replace, or pay cash settlements to thousands of vehicle owners who discover they have purchased lemons.
All you have to do is fill out a contact form or call our Helpline. We will assess your problems free of cost because the law makes Toyota pay lemon law fees.
Brian Jones spent more than 30 years working as an ASE Certified Master Tech and Parts Specialist at multiple dealerships. Brian has become an authority in the industry, traveling across the country to consult for car dealerships and contributing his expertise as a writer for several major automotive publications. In his spare time, Brian enjoys working on pickup trucks, muscle cars, Jeeps and anything related to motorsports.
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