2017 Toyota Highlander

March 5th purchased a battery from Autozone Z net Fit Match that caused cascading electrical and life -safety risk while traveling from hewitt, TX to Washington DC for our families spring break trip including 4 minor children. Component: 12-Volt Battery / Electrical System / Power Steering / Service Brakes Summary: Vehicle suffered catastrophic failure of Power Steering and Braking systems while in motion due to the installation of an incompatible lead-acid battery recommended by AutoZone’s 'Z-Net' catalog. Despite Toyota Technical Service Bulletin T-TT-0523-19 (Jan 2019) stating this VIN requires an Enhanced Flooded Battery (EFB/AGM) for its Stop-Start system, the retailer’s database continues to misidentify standard batteries as compatible. This mismatch causes a voltage drop that disables critical safety modules ('Limp Mode'). I have video evidence of the catalog error. This is a systemic misrepresentation affecting 2017+ Toyota Highlander safety compliance.

Formal Complaint to NHTSA – Summary I am submitting this formal complaint regarding repeated mechanical and electrical failures involving my 2017 Toyota Highlander, purchased as a Toyota Gold-Certified vehicle with an extended Platinum Warranty. Despite strictly following Toyota’s maintenance guidelines and using only certified dealerships for all services, the vehicle has become inoperable multiple times, requiring five separate tows and resulting in repair costs exceeding $10,000. In June 2025, a Toyota dealership replaced the engine after diagnosing a warped head due to water pump failure. Following this, the vehicle began experiencing repeated charging system failures and electrical malfunctions. Multiple components—including the alternator, battery, and sensors—were replaced at another Toyota dealership based on ongoing issues, but the problems persisted. On September 2, 2025, a Toyota technician identified a missing ground wire nut as the likely root cause of these electrical failures. He confirmed the issue originated during the engine installation and that the unsecured ground caused system malfunctions. After repairs, the vehicle was again returned with a loud engine knocking noise, later traced to an improperly secured component from a prior repair. These events have raised significant concerns for the safety of myself and my family. Improper installation of major components and misdiagnosis by certified service providers have led to hazardous driving conditions, unexpected vehicle shutdowns, and unnecessary costs. I am requesting that the National Highway Traffic Safety Administration investigate this matter for potential safety defects related to improper engine installation, grounding failures, and faulty electrical diagnosis by certified Toyota service centers. Documentation, invoices, and repair records are available upon request. Thank you for your attention to this critical safety issue.

As the electronic back hitch was closing, I pressed the Start Engine button and the vehicle dashboard lit up but would not start. Then I pressed the button again and it said the Ignition is On. Pressed again to shut off. Vehicle made a bunch of clicking noises but would not start. Disconnected battery to “re boot” electrical system… but a charger on battery and then the vehicle started. BUT the ! And Check Engine light was now on… saying take to your dealer… Check AWD. Drove vehicle at lunch time… and warning light and check engine light just went off! So weird!

2017 Highlander with the Auto Start/Stop. It will sometimes go completely dead when idling, like at a stop light. Completely dead meaning zero electricity - no lights. This will last a couple of seconds. But one day, the car died at a stop light right. No power. Completely dead. Couldn’t turn on my hazard lights Gears were stuck. Couldn’t shift gears.

While accelerating onto highways, my Toyota Highlander suddenly misfires, causing rough engine and a natural response to decelerate instead of continuing to accelerate. The ignition coil was blamed, I replace and then a week later it happens again while trying to accelerate on the highway. Another replacement and then it happens again a third time. There was a known issue under Toyota’s TSB 0148-19, where engine computers were reprogrammed and all coils replaced. My vehicle model year and engine model but doesn’t show this TSB. I am aware TSBs are not recalls, but the sudden repeat engine misfires, all in a year, while accelerating to highway speeds, is a concern.

Hi- i have always upkeep the maintenance on my vehicle and take pride taking care of it . But now out of nowhere my vehicle throttle was loose the mechanics can’t explain why and now the transmission is not working i have explained to them them driving the car does seem to stop them feels like it wasn’t to accelerate while driving. I don’t know if anyone else have reported this issue but it doesn’t make sense that for a vehicle le that’s been greatly taken care of the transmission is went out .

While braked at a red light, my vehicle completely turned off. The engine would not restart, and all electrical panel light indicators did not come back on. I could not even turn on my hazards. The whole car was dead. After about a minute, I was able to restart the vehicle, but it took 5 attempts. I changed my battery two months ago, and just had my car checked by a mechanic and nothing was found to be the problem. No warning lamps or other messages were displayed. About 6 months ago, my car did something similar to this and stalled on the freeway in bumper to bumper traffic. However, this time the electrical panel light indicators came back on. No warning messages displayed. The car restarted after only one try. This is really dangerous to have a vehicle loose all power and completely die out!