NHTSA Complaint #11478763 — 2016 HYUNDAI SONATA PLUG-IN HYBRID

My 2016 plug in hybrid Sonata repeatedly inidcates that there is "high system temperature switching to hybrid mode." This first happened on my first long trip in the car in 10/21 and has happened repeatedly since. This happens at all temperatures, including moderate temperatures (mid 70s). It seems to happen randomly, such as when battery has several miles of charge left in it, when it is fully discharged, and repeatedly when the car is already running in hybrid mode, which a driver could interpret means that the engine is about to shut down, as I did on a long trip. I have taken it to two separate dealers, and the only thing they did was replace the fuel pump, which did not solve the problem. In addition, the battery life has reduced greatly, despite the fact that I always fully discharge and recharge the batter. As you can see from the attached Hyundai forum comments, this appears to be a prevalent problem for this make and model car and no relief from the manufacturer appears to be on the horizon.