Scheduled Pre-warm not working?

Admittedly I haven't had a lot of chance to play with this; it's is my first winter with the Prime.

Is it charging when you set a departure time? I believe climate prep works only in the last 10 minutes before the scheduled departure.

I do make good use of the remote AC button, to start climate prep on demand while charging, 5-10 min before heading out.

 

It should work. I think I've got it to work for pre-programmed departure times, but I don't like to do that generally because I live at the top of the escarpment and usually am heading downtown. Yesterday, I had let it fully charge in the morning before unplugging, and the ICE actually kicked on as I was braking down the hill! I've read elsewhere that's what is supposed to happen when it's cold and the battery is full...

 

Have you reviewed the part of the manual, “Using the charging timer function”? It’s on p.154 of my 2019 manual. Have you selected the right days of the week, and AM? (I use 24 hour clocks so I’m never hit by this.).

You might try the “next charging event” override, to see if climate prep works with that.

When are you getting interior windshield icing... when it’s parked, or when driving? That shouldn’t be happening.

 

There are several conditions that must be met for remote AC to work. For example the doors must have been closed (and locked? I'm not sure) for at least a few minutes, and there needs to be a certain amount of charge in the battery. If you open a door it stops.

The cycle only runs for 10 minutes, which is just barely enough time for it to start getting warm. If you don't get in just as it's finishing you probably won't notice anything at all. You should be able to hear the compressor and fan running if you walk by the car.

I think it also uses the last temperature setting you set on the climate control, but it does still work if you leave it set to Off when you park.

Also, in case it's not obvious you have to hold the AC button for a second or two until the turn signals flash.

 

I have never had interior icing problem but since I park my car outside, I deal with external icing problem all the times. Is your car parked in garage? What was the ambient temperature when you tried the climate prep? The heat pump is not effective below 14F (-10C). In fact, in my experience, any temperature below freezing, the heat pump is not very effective in producing enough heat to thaw the ice builup on the windshield (in my case outside). The climate prep uses only the traction battery operated heat pump to heat up at the last setting you left when you stopped your car. If you want your front windshield to be defrosted, you must leave the HVAC with direction of air to WINDOW. Front defrosting (the operated by the button on the left side of the screen) will not turn on while plugged in no matter what you do. For that function to operate, ICE must turn on, which is not possible while the car is plugged.

 

I live in a cold climate, and the temp has started dropping below -15C recently. I didn't realize the vehicle no longer becomes an EV at colder temperatures... as soon as I turn on the heat, the engine fires up and i'm wondering why i spent an extra 10K on a battery that i can only use for half the year... if that was the case i probably would have just gotten a normal hybrid and...anyway..I digress

the scheduled departure, or using the remote to pre- warm the car doesnt seem to really do anything for me, and the front windshield seems to fog up as soon as i sit in the vehicle, unless i have the front defrost cranked, and of course the ICE burning gas.

this morning i got up and started the car, cranked the heat, and went back inside, assuming the engine would fire up and warm up the car. i was very frustrated to come out to a frosty prius prime that had decided to turn itself off and not defrost the windshield. I'm wondering if it shut itself off because the key fob was with me in the house, or the vehicle was still plugged in...regardless i'm pretty disappointed in this vehicle... i bought it as a way to commute to work and burn as little fossil fuel as possible... and now i'm burning gas to warm up the vehicle? Did anyone at toyota think of electric heat? Sure they draw a lot of power, but i mean, i can turn on my steering wheel warmer and heated seats without the engine firing up...

granted i live in a very cold climate during the winter months, but as i was driving last night freezing my nice person off in EV mode with the climate control OFF and the windows cracked to avoid frosting up the window, I really regretted my decision of buying this car...and its only going to get colder for the next couple of months.

anyway, sorry for the rant, i'm a little bitter right now...

 

Sorry to here your disappointment, but I will try to answer some of your questions anyway. As you found out yourself, the remote pre-warm will not work in temperature below -10C (14F) as it is solely operating from the traction battery using the heat pump. The heat pump, while it is very efficient in milder climate, is not effective at all in extreme cold. Below -10C, ICE has to start to heat the cabin.

As you guessed, with the charge cord plugged in, you can not start the car. Car will not go into READY mode. Your car shuts down after short time because it was not in READY mode. The engine can not come on while the car is plugged in. Since the front window defrost requires the ICE to be on, you can not perform that task with plug in. You have two choices. Leave the climate control with manual setting with air direction to Window and fan to all the way to max and temperature to HI. This can send warm air to window if the heat pump can generate heat. However, if the temperature is below -15C, your only choice is to unplug the charge cord and start the car to READY, then push the front window defrost button. This will immediately start the engine and defrost the window. One another option, which I use all the time, is variation to those two. Unplug the charge cord and start the car into READY mode, then switch to HV. This too start the engine. I then set the climate control to Max fan, Temp 70F, Direction of air to Window, A/C off. This setting will make the all the heat to go to window and lower cabin. It sometimes takes good 5 min of pre heating like this for me to completely thaw very thick ice formed on windshield. Yes, it uses gas for this process, but it would be the same amount of gas used by pure hybrid Prius. And I still have ~25miles of traction battery EV range left to drive once the engine and battery is warmed up.

Plug-In hybrid and BEV have quite bit of disadvantage in colder climate, but it can also be a advantage in that battery does not heat up like in very hot climate making it last longer. Yes, I agree with you that if I had to pay $10K more than pure hybrid Prius for my PRIME, I would have been angry as you are, but in my case and for many of buyers in the US, incentives and tax credit made the final cost of PRIME to be cheaper than the regular Prius. Didn't Canada also offer incentives on PHEV? In any case, for your climate I suggest mixing HV and EV depending on your heat need to maximize EV ranges during colder month and for summer your can have pure EV.

 

The heat pump won't run unless the car is in READY mode, since it runs off the HV battery. So if it's plugged in the only way to get the heat pump to run is:

• Use the Remote AC button (with the climate controls pre-set to blow air at the windshield)
• Set a departure time and turn on pre-conditioning (same requirement to pre-set the setting you want)

There is a phrase buried somewhere deep in the owner's manual that says the heat/AC output may be limited during remote AC or pre-conditioning. It's already weak enough, but the limited power output sometimes make is seem like it's not working at all. If my windshield is covered in ice I'll run 3-4 Remote AC cycles before I leave. Each cycle is 10 minutes. After 3-4 cycles the windshield is usually warm enough to brush off most of the ice without scraping it.

If I'm in a hurry or didn't plan ahead, I'll unplug the car and start it (READY mode), and then the heat pump can work at full power. That way takes aboout 10 minutes to sufficiently warm up the windshield. If I'm in even more of a hurry I'll use the defrost button and let it start the engine, but I don't usually have to do that. Most of the time it's mild enough here that I can use EV mode most of the winter.

If you can stand not using the heat, you can use EV mode below 12-14F if you drive with the climate control off, and if the battery is sufficiently warm from being plugged in. That's pretty chilly, but it might be good for a short trip where you don't want/need the engine to run. My personal record is making it to work (25 minutes) on a 9 degree F morning in EV mode with the heat off (but the seat heater on High of course).

Interior icing happens if snow from your boots melts onto the floor, then condenses on the glass as the car cools, then freezes as the glass cools more. It's really annoying, but my only suggestion would be to keep the interior of the car as dry as possible. If you have all weather floor mats, dump out any water when you park.

 

A trick I've used for years is to turn off the heater while I'm clearing snow & ice off the car. This accomplishes two things. First, if the air intake vent is covered with snow, turning on the fan will suck the snow into the car and throw it straight onto the window. Second, it gives the engine a minute or two to build up some heat before you start drawing it off. Not a big deal, but every little bit helps.

Ed

 

I think you quoted a wrong comment? Your comment should be addressed to the OP or @Paul Prime.