Prime may start ICE in EV mode if Windshield Defogger switched on

Then that's optimal for the Prime.

It will start despite being in Ev mode when:

• State of charge is low and you ask for near full-throttle.
• Every 200km (200 miles?) to keep things lubricated, etc.
• When you turn on the front defroster.
• When you ask for heat and it's below 14F/-10C outside.

That's all pretty rare stuff for most people.

 

Just to clarify: there are two "radiators" in a car's cabin ventilation system. One's got engine coolant, the other's got the AC fluid. They can work independently, or in tandem.

 

Okay, regarding the front defroster.

There are two ways to do it. You can put it on heat and direct the heat to the forward windshield vents, or you can hit defrost mode. The engine only needs to start in the later case. The defrost mode will also dehumidify the air by running the heat pump in cooling (air conditioning) mode. To get heat in such a case, you need warm engine coolant so the engine needs to be running.

If you don't need dehumidification, which you probably won't if you preheat (because no one is in the car breathing and thus adding humidity), then just forward heat may do the job.

You can also switch back and forth between heat and A/C from the heat pump without starting the engine.

 

I couldn't find it in a Toyota document. Do you have a reference?

 

Well, I was looking for the thread where ICE comes on even with climate off, front and rear defroster off and outside temperature is 46 F and EVSE was plugged in to utilize battery warmer function. I started out going 25 MPH for about 3/4 mile then gently accelerated to 35 MPH and BOOM! ICE kicked in, what gives? Checked how many miles since last time ICE kicked in it was 88.3 miles so it's not the 200 mile, ICE kick in interval.

 

Emphasis mine:

EV driving may be canceled automatically in the following circumstances:
●When vehicle speed is more than approximately 84 mph (135 km/h).
●When power is needed temporarily, for example when the accelerator pedal is depressed firmly or when accelerating suddenly.*
●When the temperature of the hybrid system is high.
The vehicle has been left in the sun, driven on a hill, driven at high speeds, etc.
●When the temperature of the hybrid system is low.
●When the heater is switched on when the outside temperature is below
about 14°F (-10°C).
●When the windshield defogger switch is pressed. (→P. 491, 501)
●When the system determines that the gasoline engine needs to be started.
The gasoline engine may also operate in circumstances other than those
listed above, depending on conditions.
*: When traveling in the EV auto mode only

 

None of the above applied to me except for the battery warming feature, my battery was not warm enough.

 

Of course it did - look at the bold text.

 

Yup, I edited my response before you quoted me

 

There's a catch-all:

"The gasoline engine may also operate in circumstances other than those listed above, depending on conditions."

 

i test drove one today. they had it warmed up when i got there, but when i put in ev mode, every time i gave it a little gas, the engine would come on. we couldn't figure it out.

my pip doesn't do that.

 

Was the battery near dead?

 

2 miles of ev left.

 

So, it did that to me as well but only at pretty high throttle settings.

I don't think two-motor usage is possible when the battery is nearly drained so it'll start doing that near the end of the Ev range at high throttle settings.

 

that's probably it, but i'm a granny on the pedal. the pip doesn't do it. plus i was in eco mode which desensitizes the pedal. i would have to drive it again.

 

Worth trying EV auto in this circumstance. I think EV auto does not use dual motors mode.