2020 Prius Prime (plugin basic) won't start in extreme cold. Mods please move this if required. I joined this group in hopes that someone may have an answer for my problem as per below: Equipped; 2020 Prius prime (plugin basic) -30+ C weather in NWT Canada Fully charged LILO battery Fully charged 12v battery Battery blanket, Block heater and Synthetic oil rated for NWT winters. Attempt to start; Break peddle down, push button, electronics (lights Nav etc) work. Engine does not crank, nor does EV mode engage. I am at my wits end. Is this a design flaw for -30C++ (-50C) weather? Thoughts?
Hello and welcome to PriusChat! If the car has been parked and cold soaked such that the battery temperature is -30°C (I'm guessing it'll take a couple of days to get there), then it won't start. You'll have to plug it in so that the battery heater can operate and bring the temperature of the battery above -30°C. Also, if the engine doesn't start, try forcing hybrid mode by pressing the HV/EV button. By default, the car will start in EV mode every time. Alternatively, turning on the front defroster should also kick the engine on. Page 92 of the owner's manual: Relating to the battery heater: Relating to the battery warming control (vehicle parked and plugged in beyond 3 days)
@Tideland Prius, not that I need to know, but I'm curious and others might be puzzled, too, what does it mean by "insulating" the battery?
Yep, sound like this is the case the THS system shut down due to extremely low temperature. Just a note that the -22F(-30C) limit is the temperature of the battery pack, not the ambient temperature. When we had a -16F(-27F) low temperature, the traction battery compartment temp was almost 10F higher that morning and the car started fine. Yeah, that part of the manual is all non-sense. I have no idea what it means. @john1701a has shown that his PP plugged to L2 EVSE continued to use some kWh daily, presumably for the Traction Battery Heater function beyond 3 days. And, the manual makes it sound like this mysterious "Hybrid Warming Control" feature exists only for Canadian or Alaskan PP. I have not yet read any evidence that Canadian PP has any different cold temp feature than the lower US. Besides, if this feature is so important to the car, why not make it an available option for the US models? I live close enough to the Canadian border that our climate is mostly colder than temperate regions of the Canadian provinces. BTW, I was experimenting with how the car behaves without the "Traction Battery Heater". This option is operator selectable in the setting menu. Most people don't even know about this setting. All PP I purchased had this option ON when I purchased, but I have never tested selecting the option to OFF. As I stated above, the car started fine when the ambient temp was -16F several weeks ago. We since then had a couple days of severe cold with nighttime lows reaching -26F. But I could not test my PP on those occasions. It was in a body shop for a minor repair. for the last two weeks. We may not get another cold spell as low as -26F. The current forecast for the next 10 days has the lowest temp predicted at -18F late next week, but the temp swings back up to +35F the following day. I don't think we have prolonged extreme cold days with temp below -22F(-30C) that will shut down my PP in our region unlike where the OP is.
As suggested already, try warming the traction battery using the charge cord. Start by insuring you have the battery heat function selected. Check the owner’s manual for where to find it in the menu. Then plug in the charge cord even though the battery is fully charged. The green lights at the port should glow green indicating current flow for the heat function. Please report back on how things work out for you. This is a new situation for many of us and I would like to learn from it. A portable heater that can safely be used in the cabin would also help. Keep in mind that it will take many hours for the traction battery to warm up given its size and if cold soaked. iPhone ?
I’m not actually sure. I didn’t think to ask the engineers at that time. Could it be a translation issue? Perhaps by “insulate” they just mean to protect it from dropping to -30°C? (Rather than actually providing insulation as in a blanket or similar)
UPDATE: Thank you for your replies. The car will absolutely not start in -40 cold. The Block heater Toyota installed (no change) does not provide enough heat to warm the engine. The instrument panel oil light remains on. Changing to Power mode does nothing. Putting on the defrost does not fire the engine. The
I discussed this with someone here, I think. Best guess is that instead of "insulate", they meant "isolate" as in disconnect. Ed
I've started my 2020 PP multiple times at -30C with no problems. No battery blanket, no block heater, 0W16 oil, no garage. We've had -40C weather, but I haven't had to start the car. The block heater is a joke. It's only rated for 200W. They can't put in a more powerful heater because then the block heater plus the charging current for the traction battery could overload the 15A circuit. So the instrument panel lights up, but there are no error messages shown? I'm assuming that the Ready light does *NOT* turn on. Is that correct? No check engine light? No snarky message that "It's too frickin' cold to go anywhere!"?. Check the list of items in the manual on page 697: "If the hybrid system will not start". Note that one of those items says that if the hybrid battery is below -30C the hybrid system may not start. One sneaky one is that the hybrid system won't start if the charge cable is plugged in. If the hybrid system doesn't start, there's no power to start the ICE. On page 698 there's an emergency start function you could try. Ed
