2025 Honda Odyssey Powertrain & Transmission Problems

The contact owns a 2025 Honda Odyssey. The contact stated that while driving at an undisclosed speed, the accelerator pedal was depressed; however, the vehicle failed to accelerate as intended. The failure had occurred while driving from a stoplight, while the auto idle system was enabled. There was no warning light illuminated. The vehicle was not diagnosed or repaired by an independent mechanic or dealer. The dealer was made aware of the failure. The contact was advised that a diagnostic test was needed to determine the cause of the failure. The failure had occurred three times; however, the failure had not reoccurred after turning off the vehicle. The dealer informed the contact that the failure might not be duplicated. The manufacturer was not made aware of the failure. The failure mileage was approximately 12,549.

Dear NHTSA, I am submitting a safety complaint regarding my 2025 Honda Odyssey, which has been diagnosed with a transmission failure requiring full replacement due to faulty internal seals. The vehicle is less than one year old, and this type of premature failure raises serious safety concerns. I first became aware that something might be wrong during a routine oil change on November 11, when technicians noticed signs that the transmission might be leaking or malfunctioning. I continued to monitor the vehicle, and on November 28, I was informed that the entire transmission must be replaced due to faulty seals inside the transmission assembly. A critical component like the transmission should not fail this early in the life of the vehicle, and a structural defect such as faulty seals may indicate a manufacturing issue that could affect other vehicles of the same model and year. Information from the dealership: SHEEHY HONDA OF ALEXANDRIA Diagnosed transmission failure caused by faulty seals Recommended repair: Complete transmission replacement Explanation: Premature failure of internal transmission seals leading to fluid loss and unsafe operation Repairs completed so far: Diagnostic inspections confirming failure This vehicle is used to transport children, and a sudden transmission failure presents a significant safety risk. For a new vehicle to require a full transmission replacement within its first year of use is highly concerning. I am requesting that NHTSA review this issue to determine whether other 2025 Honda Odyssey vehicles may also be experiencing similar premature transmission failures. Thank you for your attention to this matter. I can provide repair documentation, inspection notes, photos, or any additional information upon request. Sincerely, Allison Epps 334-464-0233 alijepps@gmail.com Vehicle: 2025 Honda Odyssey

I came to a stop at a stop sign. Then "auto off" shut off the engine. Next, the vehicle went into park. A message came on screen telling me to press the brake and the start button. Doing so had no effect. Cars behind me started honking. After repeatedly stabbing the start button and opening and closing my driver's door, the vehicle eventually rebooted, and the engine started as normal. This caused a dangerous situation where other cars went into opposing traffic to get around me.

The idle stop system is malfunctioning. I had it inspected once previously and now trying to get it inspected again for the same occurring issue. The dealership continues to tell me to turn off the idle stop feature on the vehicle. My safety was put at risk because of the vehicle stalling and not kicking back on while being stopped at a redlight on a busy 4 lane highway multiple times now. The first time, I was by myself. The second time, my 8-month-old was in the vehicle with me. This causes a lot of panic as there are impatient drivers around me since I am unable to move my vehicle. I fear that this could happen on a freeway if there was construction, an accident or even while trying to turn in an intersection and getting hit because I can’t move my vehicle and often have my two small children with me. The first time the idle stop stalled, it occurred twice in a week. The first time was rather quick, and the engine kicked over quickly so I did not think anything more of it. The second time which happened a few days later (9/17/25), took about 5 minutes to get the engine going again and moving on the road (4 lane highway). I took it back to my local Honda dealership where they performed a diagnostic test and discovered the battery had dipped down to 7.22V when trying to restart, the battery failed the battery test and ended up being replaced with a new battery. The idle stop issue has now happened for a third time (10/21/25), with the same issues occurring and I am waiting to be able to get back into Honda. The vehicle has only been looked at by my local Honda dealership. There were no warning lamps, messages, or other notifications prior to the failure. I received a warning on the dashboard after the events occurred on how to start the vehicle. This is very disappointing as a new Honda owner. My husband and I decided on Honda over other car companies due to their reliability and this has now become a constant worry.

Vehicle shut off and put itself in park leaving a stop light. Was hard to restart.

On June 14th 2025, I reversed up my driveway, uphill, shifted to neutral to allow the vehicle to roll downhill a bit so I could straighten it out. While rolling forward, the transmission was jammed into park with no warning or interaction from me, causing my head to sling forwards in a whiplash fashion from the abrupt change in inertia. This was both harmful to me, to the transmission, and is a major defect. Engaging a transmission into park while moving is reckless, harmful and extremely dangerous. The failing component is most likely the transmission control unit and is available for inspection upon request, but has not been inspected by anyone other than myself. The problem is reproducible by me.