So sometimes in the middle of completely normal driving conditions (e.g. stopped at a red light after driving 30 mph on a flat street), with a fully charged battery, HV charge mode will just pop on. When this happens it usually cannot be turned off unless the car is shut off completely and restarted. At these times, trying to manually engage HV charge mode will generate an error message that says "HV Charge Mode at Maximum Limit, Plug In to Complete Charge"--but the car nonetheless stays in HV Charge mode until being shut down. I tried to get the dealer to fix it but of course it didn't happen when they test drove it (this happens say once every two weeks randomly), and no one at the dealer had ever heard of the problem. Ideas?