I have a 2024 Prius Prime. Is there any way to prevent the ICE starting up in cold weather? I've noticed when the weather/battery is cold, the engine will start while in electric mode, presumably to warm the battery. This the exact opposite of what I wanted this car for. I would love to know of any way to prevent the engine from running when the battery is cold. My commute is about1500 feet. In cold weather the engine starts about 100 feet from my driveway.
One solution might be to bundle up and walk the 1,500 feet. I’m not an owner of the plug-in but I suspect those systems are automated based on the car’s diagnostics and not something you can override.
At what temperatures are you seeing this? What fraction of mornings is it cold enough to force this mode? I haven't had my related '24 RAV Prime out in much serious cold yet (missed most of last ski season due to injury), so haven't learned all its temperature thresholds. While traveling, only once has it been started in cold enough conditions to immediately bypass EV mode and go straight to HV, probably +4F that morning (?). On several morning in the teens, I needed the front defrost to melt off the windshield before moving, also forcing the ICE on. But garaged at home in a milder coastal climate, haven't yet dealt with unwanted ICE operation, it doesn't get cold enough here every winter. I also haven't yet run into a "100 feet from the driveway" threshold in this RAV. In my previous Gen3 Prii non-plug-in, that threshold (actually, 10-15 seconds from start) was 68F.
There's a bunch of things that will trigger the ICE; most of which is designed to protect the overall system. Overriding it will likely cause damage, over the long run and reduce reliability. Toyota engineers did a fairly decent job of protecting the overall system. PS; keep an eye on your 12V aux. battery level. Those short hops, you'll be running at a deficit and slowly draw down that battery - not enough time to recharge/recoup-orate.
Easy... Just need to install an engine block heater and set it up so if you forget to unplug when you drive off in a rush it unplugs itself.
I appears I've under estimated level of maieutics here. The road between my home and work is winding and mostly has 1.5 inches between the fog line and a ditch - not much walking room - it's also a steep hill. I guess I'll just have to remove the sparkplugs and disconnect the fuel injectors in the parking lot before I drive home.
Your probably joking, but if your not - just disconnect the ignition coils. Expect a check engine lamp.
I find it fascinating how you assumed I was leaving my home when in fact I was referring to the opposite. Going to work my battery is warm - the car started out in my heated garage. But after being at work for 4 hours in 10F-15F degree weather, the battery is cold enough for the ICE to start about 100' from my house as I go home for lunch. I guess for the first 1400' of my drive home, the computer is pondering life's other more important mysteries - perhaps like, "why do so many people answer simple direct questions with more questions?"
If you’re going down a steep hill with a pretty full, and cold, EV battery the ICE will start. I have had this happen many times. The solution for me is to be very gentle on the brake pedal or switch the car into neutral on the steep part of the downhill.
Simple questions often lack sufficient case detail to properly answer more complex problems. Necessary or relevant variables are still unknowns, leaving the matter under-defined. Snooty slapbacks are not a productive path towards pinning down those unknowns.
FWIW; Placing the car in neutral while driving is technically illegal, in the lower 48 and will place undue wear on the braking system. This disables regenerative braking; not sure how it would effect Safety-sense system. Since your stopping regenerative braking, you'll need to apply the brakes more often to control the decent of the car. Depending on how long and steep that hill is, would you heat up the brakes to a point that you can't stop when you get to the bottom? I had that happen to me, way back in high school. Myself and a bunch of friends piled into my little CIVIC - I was simply LUCKY that the intersection was clear - I was the only one at that intersection with a stop sign. Any collision would've been my fault along with any injuries my friends would've sustained. Ole to be young and stupid again........
Another (perhaps partial) solution is to not have a fully charged battery at the top of the hill. Leave some uncharged, so that there is enough empty capacity to absorb the downhill regeneration. Though when cold, the battery's allowed charge rate is reduced, so the regeneration could still exceed the battery's rate limit. But at least, leaving some space in it should let the car go farther downhill before triggering the ICE. That will depend strongly on the total elevation change. A couple hundred vertical feet should be no problem, a couple thousand vertical feet will be a problem. It seems that with today's light passenger vehicles, the numerous people who don't properly downshift on 7% grades at highway speed are not having safety problems after 1000 and likely 2000 feet of vertical descents. Descending in neutral with no engine drag, will cause brake problems significantly earlier. Heavier vehicles or loads, much earlier still. And old-era drum brakes earlier than today's disc brakes.
