2020 Honda Odyssey engine problems

“My 2020 Honda Odyssey EX-L intermittently fails to restart after the Auto Idle Stop feature shuts the engine off at a red light or stop. This has happened probably 10 times in the past 6 months. In order to start the engine, I must recognize that the engine isn't starting, turn off the vehicle, and turn it back on, often 2-3 times before it actually starts. This leaves the vehicle stopped in a traffic lane at an intersection with traffic trying to pass, which creates a risk of rear-end collision or cars trying to pass me. Cars have gotten into near misses trying to pass me while my vehicle is inoperable. I have no warning lamps or messages before it happens. History: The dealer performed Honda’s idle-stop software update (service bulletin 23-008) in November 2024 at about 63,100 miles. The problem continues. The battery was replaced in December 2022, and the dealer’s October 2026 inspection rated the battery “Good.” (as did a second independent auto shop). At 93,331 miles in October 2026 the dealer documented the complaint, charged a diagnosis fee, and recommended replacing the starter motor at a cost of $954.53 plus a diagnostic fee of $184.95. I contacted…”

“While Automatic IDLE was on, engine shut down at a red light. Dashboard showed message: put in park. Alternator was fine. Battery fine. I DID get the software update but this happened AGAIN. This time was able to put in park and was able to start the car. I have to remember to turn OFF Automatic IDLE to avoid this from happening again.”

“Upon starting my Honda Odyssey, the dash immediately started saying, Collision Mitigation System Problem, Adaptive Cruise Control Problem, Road Departure Mitigation System Problem, Lane Keeping Assist Problem, Auto High Beam Problem.”

“The auto idle start when I am at a red light it will turn off and put it in park. I have to restart the van and put it back in drive. I believe this to be a safety issue. I have my kids with me and its dangerous. I would like to know what can be done and why hasn't this been a recall. I have to remember to push the auto idle button each time I get in to drive otherwise Im afraid ill get stranded at an intersection. Its been going on for at least a year and the dealership thought it was the battery we have replaced the battery so that is not the issue.”

“The contact owns a 2020 Honda Odyssey. The contact stated that while driving 45 MPH, the contact heard a knocking sound coming from the engine, and the vehicle went into LIMP Mode with the low oil warning light illuminated. The contact became aware of a burning odor coming from under the hood, and the vehicle needed to be towed. The vehicle was towed to the dealer, where it was diagnosed and determined that the connecting rod bearings had failed and the engine needed to be replaced. The vehicle was not repaired. The failure mileage was approximately 50,000.”

“Stopped at a light, auto idle stop engaged, engine shut off normally. The moment I pressed the gas, everything died — engine and all electronics. I pressed the start button two or three times with no response, then it finally started. It was still in Drive. The hazards wouldn't turn on right after, then everything gradually came back to normal.”