ICE is Running, SoC is high, Car is Parked - ??!?

It was probably due to your heater setting. The only way to generate heat for the cabin is to run the ICE to warm the coolant.

 

Repeat the situation, and lower the cabin temp, see if engine will then shut down. I've found, especially when the car's halfway through warm up, I can turn engine off/on via cabin temp setting.

 

For that experiment, you have to lower the cabin temp all the way down to its lowest setting, and it just a few degrees.

 

With cooler temps your ICE will run more. First to warm up the ICE pollution control systems and second to warm the cabin. The ICE will shut down if demands permit, but it will run more than when the temps are a bit milder.

 

I'll often stop at a red light, about 1/2 km from home. Coolant temp typically around 50C. In that scenario, somewhere around 21C cabin temp setting is the threshold: higher, engine goes on, lower, it goes off. 21C's something like 68F?

And yeah, ambient temps are a factor too.

 

No... if you have the heater set to any temperature, the engine will start in order to heat the coolant. And it will restart, and restart.... Remember, my Prius is a plug-in, so the engine in my car can stay off even if I drive ten miles. But if the cabin heater is set to any temperature above the very lowest setting, the engine will start and restart to keep the coolant warm.

 

Ok, apples/oranges. But, OP does not have a plug-in.

 

Just switch the AC off. Works for me. Engine goes off straight away.

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Very foggy this morning and 55 degrees. I actually got a bit nippy walking in my shorts and T-shirt. I had the temperature set at 70, and I did notice that the engine came on more frequently when I was parked. But that's fine, now I know it works and it keeps me nice and toasty.

 

The AC is electric so it won't necessarily start the ICE, but if the engine is cold and the heater is above MIN, the ICE will need to start up so that the engine coolant can be warmed.

 

On the plugin yes, but neither GT4 nor OP have plugin.

 

I slept in my car once on a cold winter night. I set the air to 65 and the fan to 2, the engine came on about every 8 or 9 mins and ran for like 45 seconds at a time. Woke up seven hour later to 6 bars SOC. Used about a gallon of gas all night. Gosh I love my car ❤️

 

I think that what I'm saying applies to the standard Prius. The Plug-in just runs on electricity longer.

If I cold start and the heater is above MIN: Engine starts immediately, and it won't shut down until it's fully warmed up. :-[

 

The control I use is the Ac Auto button on the steering wheel. The Auto Climate aspect of the car blurs the distinction between the heating and the cooling aspect of AC. I agree that it is the heating aspect of AC that requires the ICE to run in order to heat the coolant so as to heat the cabin. Heater setting is in relation to cabin temp so if colder in cabin than min car setting I guess heat requirement Will turn on ICE, assuming engine is cold or insufficient heat in coolant.

May differ slightly on US models due to their electric heating element in heater.

Only sure way IMHO and in my experience to avoid ICE coming on to provide cabin heat is to turn off heat (aka AC), which is easily done on my Gen2 using aforementioned button.

(Ps I also agree that the cooling aspect of AC on my Gen2 is electric and can run without the ICE depending on state of charge.)

Posted via the PriusChat mobile app.

 

I don't see any button in my Gen4 that says "Heat." So I just make sure the "AC" button is off, and turn up the Temp.

Gotta keep things simple for us old dudes.

 

Just remember: In a hybrid, all energy comes from gasoline. The battery is just a storage unit not a source of energy. The less energy you use (or request) the less gasoline you'll use.

 

If the heater is set to MIN, it's off. So the engine coolant does not need to be heated. Therefore, the engine will not start in order to warm or reheat the engine coolant.

This is easier to observe with a Plug-in Prius but it will happen with any Prius: When you put the Prius in Ready and heater temp is MIN, the engine will not start. But if you then raise the heater temp and start the fan, the engine will immediately start.