ICE in EV Mode ... Again

It happened again today, but this time I was more prepared to investigate. I disconnected the charger in the garage after letting it charge overnight. I got in the car and started it, and it started in EV mode as displayed above the speedometer. The display initialized by telling me the charge was complete and showed 13.9 miles EV range. Driving under 40 mph until the first traffic light I thought I felt the ICE kick off as I was braking, but after a glance to verify I was still in EV mode above the speedometer and the HSI display didn't have the little bar in the middle it as in VH mode, I chalked it up to my imagination. When I started away from the light I felt the ICE start again. I glanced at the instantaneous MPG display, which showed ~25 MPG. I switched from the HSI display to the Energy Monitor display and there it was, with arrows running from the ICE to the wheels and to the battery. A quick glance at the controls: no radio, no fan, no defrosters ... absolutely no accessories running. I let off the gas and the ICE shut off. When I depressed the accelerator again the ICE started again. It was behaving exactly like I was in HV mode, but the battery still showed 13 miles EV range and the EV above the speedometer was lit. I tried toggling the EV/HV mode button, but it made no difference. I had to pull over and shut the car off and start it again to achieve normal EV mode. After that it behaved normally until the EV range was depleted.

 

It can't be the cold because the temperature was 66°F.

 

Except the engine was shutting off when I let off the gas and starting again when I pushed the gas, exactly the same as it behaves in HV mode. This wasn't a case of the ICE running until it was warm. It continued to behave this way for about 5 or 6 minutes until I pulled over. It was simply operating in HV mode despite having 13 miles of range and being set to EV mode.

 

Absolutely and unequivocally not. I start so slow that people honk at me and there's no defroster necessary at almost 70 degrees on a sunny day.

I watched no less than five times the engine shut off on the Energy Monitor when I released to accelerator and start again when I pressed it. The first time this happened to me it might have been a mistake. There is no mistake in this case. I even had a passenger with me as a witness this time.

I called a Toyota dealership that I knew had a service department open on Sunday to see if they had someone available to look at it if I brought it in while still in this bizarre state, but they only do oil changes on Sunday and don't have any Prius techs.

 

Even if this is what happened, the ICE wouldn't shut off when I reached the light, start again when I began again and shut off when I released the accelerator ... numerous times.

 

As do I. It's never been below thirty degrees here in this century.

 

People here are very incredulous. Next time I'm taking a video, safety be damned.