Sadly, my commute is beyond the EV range. Hence, I choose when to use EV mode or not. Often when I try to switch back into EV mode on the highway, it will not!? I have to play with going faster and slower AND/OR toggling the 'HV / EV' button a few more times... Sometimes I even try the 'EV Auto' button too. Sometimes it will go miles without switching back into EV mode. It just seems to do it when it finally feels like it. The screen says 'EV mode' but the car image stays empty, instead of saying EV. Also, the EV miles do not decrease... So it is definitely not running EV. Very frustrating. Is this normal? What am I missing?
The only way know to work is to stop and restart the car. I comes out in EV mode. All other means appears to have poorly or undefined mechanisms. Bob Wilson
Once the car goes into ICE warm-up mode, it continues until completed. I see this most often in EV mode if I demand too much power.
If you have the front defroster on (orange led lit) ICE will continue to run. Turn off front defroster.
that's only if you start out in EV mode after overnight charging. after going 5 miles in EV ICE does not kick in when using CC
Has anyone found out more about this problem? The answers above all seem reasonably plausible, but they're kind of all over the place. Most of my trips are less than five miles, and in the winter I nearly always have to turn on the defroster for the first mile or so. ADO I have no choice but to drive around all winter in hybrid mode, using gas, when I'd like to be in EV mode?
Typically in conventional cars defrost mode runs the a/c to dehumidify the air blowing on the windshield. Since this is impossible with the single heat pump providing EITHER heat or a/c but not both the ICE provides heat and the heat pump provides the a/c when in front defrost mode. Yes?
While the car is plugged in and you just got up, press the "A/C" on the key fob. This starts a 30 min., preconditioning of the car that includes warming the cabin. Get dressed and walk to car. If covered with snow/sleet, take a short broom and brush off the windows. Disconnect the plug and drive to work. When SOC reaches ~90%, you can use CC. Front defrost will start the ICE and keep it on. If the ICE comes and you want it off: safely stop; power down the car, and; READY the car. Bob Wilson
Yes, that mode seems to allow it to stay in EV mode. It doesn't defog as well as heat plus AC, but it's good enough a lot of the time. In that mode you don't get a "climate score", and the heat pump seems to use a lot of energy, but at least the engine isn't running. If you have it in feet only mode that will also very slightly defog the windshield. Feet plus a high fan speed can work decently well.
Not sure if it is clear from earlier posts, but in the Prime, you CAN get dehumidification without running the ICE. There is a condenser coil (hot) in the cabin along with an evaporator (cold), and the cabin air can be ducted over both to provide dehumidification. "Front Defrost" assumes that you need some serious heat to melt ice on the windshield, and thus turns on the ICE to get hot engine coolant. For modest amounts of fogging on the windshield, the system automatically detects that and does the dehumidification without the driver having to do anything.
It looks like you are probably right, but this article doesn't have enough detail to know about the dehumidification modes for sure. How does the heat pump work in a Toyota Prius Prime plug-in hybrid? Does the windshield fog sensor trigger an alert if the fog gets too bad? I think I read that it does, but I haven't seen it yet. For example if I manually set the climate control to face vents or a low fan speed, the car has very little it can do to defog the windshield. Presumably the conditions in the camera housing could be different than what the driver is seeing, which would explain the need for a humidity sensor where it is. Although if it's true that the amount of fog in front of the camera could be a problem, why not just heat the camera housing to get those components above the dew point? It would take relatively little electricity to do that I suspect.
