2018 Toyota Highlander Powertrain & Transmission Problems

I am reporting a documented safety defect in my 2018 Toyota Highlander (VIN: [XXX] ). On March 31, 2026, a certified technician at Groove Toyota (Work Order #XXX) performed a diagnostic inspection to investigate a severe 'airplane whine' noise. The technician verified the noise and used a stethoscope to pinpoint the source as 'very loud coming from final drive,' officially recommending a full transmission replacement at an estimated cost of $8,475. This failure is a direct mechanical match for a known factory assembly error (insufficiently bent locking tab) acknowledged by Toyota in Technical Service Bulletin T-SB-0160-18 and Customer Support Program ZJC. Despite the technician's formal diagnosis that the vehicle is mechanically unsound and requires immediate replacement for safe operation, Toyota Corporate denied my request for assistance (Case #XXX) on April 8, 2026. Toyota cited my vehicle's VIN does not fall into the customer support program, although it's essentially the same transmission, effectively refusing to remedy a documented manufacturing defect. This vehicle has excellent service records, and Toyota’s refusal to honor the spirit of the ZJC program leaves me with a documented safety risk that the manufacturer refuses to address. INFORMATION REDACTED PURSUANT TO THE FREEDOM OF INFORMATION ACT (FOIA), 5 U.S.C. 552(B)(6)

The UA80 8-speed automatic transmission failed catastrophically without any prior warning symptoms while driving on the highway. During normal acceleration to pass another vehicle, the engine revved to 5,000 RPM as the transmission slipped, then dropped to 3,000 RPM coasting. After exiting the highway approximately one mile later and coming to a stop at a red light, the transmission would no longer engage in any forward gear. The engine revs freely when placed in drive and the accelerator is pressed. Reverse still functions. The vehicle had to be towed from the roadside. This created a serious safety hazard. The driver was stranded on the side of a busy road and lost all forward propulsion without warning while operating at highway speed. The failure occurred suddenly with zero prior symptoms. The vehicle was operating normally around town earlier the same day. The driver had no advance warning of any kind, no warning lights, no unusual noises, no shifting irregularities, before the catastrophic highway failure. This is consistent with reports from other UA80 owners who describe sudden, total transmission failure at similar mileage. The loss of forward propulsion at highway speed posed an immediate safety risk to the driver and surrounding traffic. The driver had to navigate to the shoulder and then reverse off the roadway to reach a safe location to wait for a tow truck. I contacted Toyota Customer Experience at 800-331-4331 and was assigned a case number. Goodwill assistance was denied twice. I was told the system would not allow the representative to proceed. I was disconnected twice during attempts to escalate to a supervisor. My case was then closed without resolution. Over 430 NHTSA complaints have been filed regarding UA80 transmission failures across multiple Toyota and Lexus models from 2017-2024. The pattern of failure is well documented. I am requesting NHTSA investigate this transmission platform and the adequacy of Toyota's limited CSP ZJC coverage.

Currently at 113k miles. VIN # is not on the recall or extended warranty list for transmission issues, shift lag has been noticed way before 100k miles. vehicle is making squealing noise on drive, and when gas petal is press. Since no recall, but per research, I may have a faulty transmission that is left out of the Customer support program zjc, t-SB-0160-18.

Vehicle makes a whining noise like a siren when accelerating at 40mph or more when you let go of the accelerator the noise stops. I've been told by a mechanic its the transfer case or related transmission component. Toyota should declare a recall since it can cause an accident if the car stops in the middle of the highway.

2018 toyota highlander awd. Whining noise when gas is pressed. Whining stops when gas pedal not engaged. Started at 116000 mileage. Regular service done at dealer. Slippage/ delay in gear shifting (automatic). No light on dash to show there may be an issue. Bought a toyota, because they are supposed to be great cars that run long time. Not real happy to hear that they know they have quality and training issues that can seriously hurt people, and they are not doing anything about it. And “their”consumers have to eat the cost for their mistake. I hope nhtsa files another motion to cover move of the vehicle having the powertrain issue

The contact owns a 2018 Toyota Highlander. The contact stated that while driving at an undisclosed speed, the vehicle made grinding sounds while accelerating. Additionally, the vehicle jerked while shifting into gear. The vehicle was taken to the dealer, who determined that the transmission fluid was dirty and that the transmission assembly and torque converter needed to be replaced. The vehicle was not repaired. The manufacturer was made aware of the failure. The failure mileage was approximately 107,700.

Failed UA80/F Transmission needs replacement for poor manufacturing

The contact owns a 2018 Toyota Highlander. The contact stated that while driving at an undisclosed speed, the vehicle was idling roughly with an abnormal sound. The vehicle was driven to the shoulder of the road. No warning lights were illuminated. The vehicle was towed to the dealer where it was diagnosed with transmission failure. The vehicle was not repaired. The contact ordered the parts to repair the transmission but was informed that the parts were not available nationwide. The contact stated that the failure was a known failure. The manufacturer was not made aware of the failure. The failure mileage was approximately 98,340.

Transaxle (Transmission) failure. Whining noise then failed while driving freeway. Towed to dealer/mechanic and confirm failure. There was a whining sound but no engine light warnings prior to complete failure. Toyota put out a TSB for this but was never informed - POL19-04. Toyota needs to expand CSP ZJC coverage to all UA80F/UA80E-equipped vehicles exhibiting symptoms, regardless of VIN range.

The transmission has started making a whining sound just like the cars/transmissions effected buy the TSB from Toyota related to 8-speed auto transmission failures. My dealer said they have seen a lot of them and mine sounds like it, but they claim I'm not part of the TSB allowing for replacement. Toyota has a real problem with the transmissions in 2018 highlanders but they refuse to fix the problem.

Transmission whining, hard shifting on 1 and 2 and 3 JP Pauley toyota claim my 2018 Highlander is not part or TBD and neew transmission is required to fix issue quote $7300. to repair current mileage 156K

My 2018 Toyota Highlander with 143k miles has poor acceleration shift lag and a whining noise from transmission. Dealer diagnosed and found transmission is failing and in need of replacement. They quoted $9624.00 to replace and the part is on backorder and could take months to get. Toyota customer assistance has declined any assistance with the repair even though they have a extended warranty program and a customer support program for the same year vehicle and with the exact same symptoms offering complete repair coverage regardless of mileage but declined my saying I'm not eligible due to the production date of my vehicle. I feel this vehicle is now unsafe to drive due to the possibility of complete transmission failure possibly at any time on the roadway.

TANSMISSION DIED AT 102,000 MILES, 2,000 MILES OVER THE WARRANTY. Toyota said it will pay $6,000 for parts. I HAVE TO PAY TAX AND LABOR. I have been waiting over a MONTH for the parts, while my HIGHLANDER SITS ON THE Toyota DEALER'S LOT IN RIVERHEAD, NY. My wife took the car there, since the "check engine" light had turned on. After the inspection, We were afraid to take it out of the parking lot. Code P275614 torque converter presure control solenoid; faulty transmission problem. Recommended a new transmision for $11,303 plus tax. Many class action suits are being filed about TRANSMISSION PROBLEMS in HIGHLANDERS!

The contact owns a 2018 Toyota Highlander. The contact stated that while driving uphill and depressing the accelerator pedal, the vehicle decelerated and rolled backwards unexpectedly. An independent mechanic was contacted. The vehicle was inspected by a mechanic friend and diagnosed with transmission failure. The vehicle was not repaired. The manufacturer was not notified of the failure. The approximate failure mileage was 92,000.

Vehicle experienced whining noise when decelerating. Toyota dealer service technician documented the noise as coming from the transmission due to an issue with the pinion shafts. Our safety was put at risk by a potential for the transmission no longer working when driving. There were no warning lamps, messages, etc. prior to the failure. The failure occurred around 136,000 miles. All recommended services, including on the transmission, occurred at the same Toyota dealer service.

The contact owns a 2018 Toyota Highlander. The contact stated that while driving at an undisclosed speed, the vehicle inadvertently lost motive power in the middle of the roadway. The contact stated that the RPM continued to increase rapidly, but the vehicle failed to respond. No warning lights were illuminated. The vehicle was towed to an independent mechanic, who diagnosed a failure with the washer tab, designed to prevent the loosening of the nut inside the transmission, resulting in damage to the transmission. The contact was informed that the transmission needed to be replaced. The vehicle was not repaired. After investigating the failure, the contact related the failure to the Customer Support Program: ZJC. The manufacturer was notified of the failure, a case was opened, and the contact was referred to the NHTSA Hotline for assistance. The failure mileage was 104,000.

The transmission makes a whining noise, especially when pulling, as in driving up an incline. I took the 2018 Highlander to Rusty Drewing Toyota in Jefferson City, MO to be diagnosed. They said the transmission needs to be replaced. In researching the problem, I found a bulletin/recall: 7A61K20482. The bulletin says the serial number must be before 7A617E03416. I want to get on your list and hopefully, be able to get some kind of relief for this problem.

The transmission on my 2018 Highlander is failing prematurely at 80k miles in alignment with known/published customer support program ZJC. My car is not a VIN covered by the program today. Symptoms include a growing whining sound coming from the transmission and confirmed by two Toyota dealership service centers.

Transmission was slipping and hesitating from 50,000 miles up until it went completely out at 96,956. The day it went out, I pulled out onto the highway and there was no acceleration, it wouldn't move. It was flashing "traction control turned off" "check engine visit dealer" "check awd system" and the check engine light was on as well as the orange triangle with explanation point. Toyota said my vin wasn't covered under the TSB, so my extended warranty paid for most, but not all, of the transmisson and parts. They put in a new transmission but the new one does the same thing. It hesitates and slips with currently only 10,000 miles on the new one.

Transmission starting making a wining noise, and was told it will fail. Toyota is well aware of this issue.