2021 Toyota Highlander Complaints

On July 25, 2026, while driving my 2021 Toyota Highlander Hybrid at high speeds on the freeway, the vehicle experienced a sudden loss of drive power accompanied by a check engine light and a severe hybrid system error warning. The failure occurred without any prior warning or degradation in performance, forcing an immediate emergency maneuver through traffic to reach the shoulder. The vehicle was towed to Toyota of El Cajon for diagnostic evaluation. The dealership service invoice details the following findings: - Primary Failure: Primary fuel injector failure (direct injection system). - Diagnostic Behavior: The engine experienced severe cylinder misfires under load at freeway speeds when the direct injectors were commanded on. - System Impact: Engine misfires triggered a hard safety shutdown of the hybrid system, immediately cutting motive power to the wheels. - Repair Executed: Replacement of the failed fuel injector assembly Safety Concern: A primary fuel injector failure at high...

This vehicle was purchased new in 2021 with 4 original miles. Today it has 58,000 miles and has been maintained, per manufacturer recommendations, a certified Toyota dealership. At around 56,000 miles we noticed a slight whine in first gear. This was attributed to normal noise that we simply had not noticed. by 58,000 miles the while had extended to all gears and become more prominent. Research online shows that this is a known issue with the UH80 transmissions and has been since at least 2017. Toyota has a TSB for it (TSB-0008-21). This was not mentioned at the time of purchase or any of the various maintenance appointments in the last 5 years. This KNOWN issue WILL lead to complete transmission failure. This can happen while parked or in motion and can include the transmission shifting out of an active gear, locking into a gear and being unable to shift to another or park/neutral and there is no way to avoid it. I called Toyota corporate about this because I was not made aware of...

The contact owns a 2021 Toyota Highlander. The contact stated that while driving 25 MPH, there was an abnormal whining sound coming from the engine. The vehicle was taken to the dealer, where it was diagnosed with transmission failure due to a pinion shaft failure. The dealer determined that the transmission needed to be replaced. The vehicle was not repaired. The manufacturer was notified of the failure and referred the contact to the NHTSA Hotline to report the failure. The failure mileage was approximately 62,300.

Transmission is shifting very hard including a clunking noise from first gear.

The transmission has failed due to a defect within the transmission. Toyota is aware of the defect but refusing to assist owners claiming warranty expiration despite the transmission failure occurring due to a defect and not normal wear and tear. Toyota service bulletin accepting the defect. T-SB-0008-21