How To Preheat The Engine in Cold Weather

What's your parking situation like? Is it in a garage? If its on the street, do you have electrical access for it? An engine block heater will allow you to heat the interior of the car much faster once the engine is running. But because Toyota sucks at software and pretty sure will eventually charge you a fee for remote start options I'd encourage you to work with using a standard outlet-based power cord to use electric blanket style warmers around the high voltage battery pack and control/monitor the system via bluetooth or wifi. Lithium batteries are at their best around 38 degrees Celsius and keeping them near that temp when you're ready to drive in cold weather will easily make the cabin warm enough to get in and drive if you're willing to do it DIY.

 

From a different thread:

"The simplest solution is usually the right answer. Just found out the engine will start in Park, start button depressed (ready , HV mode and the accelerator pedal slightly depressed). It then continues to run for a few minutes completing it's warm up cycle before shutting down. You can get out of the car, with or without the key for that warm up cycle."

Also, my car has a Charge Mode so if the traction battery isn't full just pressing the Charge Mode button will start the engine to charge the battery

That doesn't help you with the remote start problem or warming up the interior but it will warm the engine up before you race down the highway (note, I have a 2024 Prime ).

KH

 

You could try a block heater. It's a low-tech option available for any car with a gas or diesel engine. Figure a couple-three hundred bucks installed. It's just a simple resistance heater that attaches to one of the coolant ports on your engine block.

The idea is that you plug the heater into a mains power circuit at your parking space, and the heater will warm up the engine without burning any fuel at all. You can connect them to simple on/off timers so that the engine is pre-warmed every morning.

I figure if you're already plugging in the car for traction power, it won't be a big deal to plug it in twice so that the heater can help you.

Many Canadian mechanics and auto dealers are familiar with these accessories, it should not be hard for you to get set up.

 

There seems to be some confusion here on if you want to cold start the engine or pre-warm the interior??? The PHEV does not start the engine to pre-warm the interior; it uses a heat pump that has a low temperature operations limitation. That's why the app is telling you to manually start the car. The air temperature is beyond the heat pump's capability to warm the car's interior.
When you manually get the car into "Ready" and demand cabin heat in the above described conditions - the engine will start, since the heat pump won't operate in those conditions. I believe all that is outlined in your OPS manual.....

If the goal is to pre-warm the engine; @Leadfoot J. McCoalroller above suggestion.

Hybrids operate differently from ICE only cars.
PS you can force the ICE ON by hitting the windscreen defogger button - you'll get more heat, faster; but it will impact mpgs or in your case liters/100km......

 

As pointed out, the app doesn't do a remote start of the car, but just cabin preconditioning. It is a safety call by Toyota. Neither the app nor car knows if it is parked in a poorly ventilated garage or not.

To prewarm the engine, you need to do it manually, use a block heater, or find some other remote start option.

Toyota has been making hybrids for some time now. The system program does not put a heavy on a cold engine. After the engine first starts, the car is still mostly using electric power to move until the engine finishes its warm up cycle. It can get to over 80mph in EV mode, so the engine cold starting on a highway isn't an issue.

 

Install the block heater, and start it heating at least 4 hours* in advance. Start the car in hybrid mode.

* With older-style Toyota block heater, 2 hours would be enough to warm it quite well. There was apparently a fire risk though, and a recall, so dealership replaced ours. The fix appears to be a drastic reduction in wattage: now it takes 4 hours to get tepid. Anyway, better'n nothing.

 

Presumably outdoors? Is there a full-to-the-gills garage in the equation?

 

The Prius DOES NOT have a remote start option; just an interior preconditioning function. Whomever is calling it a remote starter is misleading you and don't know what they are talking about. Toyota connect is buggy at best. I opted not to extend my subscription after the trail period because I was experiencing similar issues with the app - why pay for something that doesn't work reliability? IMHO; there are aftermarket accessories that will remote start the engine; and it's a bit tricky on a Prius, but it can be done.

Here's a link to the OEM manuals. Digital | Toyota Owners

Here's a link with other people having a similar issues and their solution.
2026 Toyota Prius Remote Start Fails in Cold New England Temps, And Owners are Trading Factory Apps for $500 Aftermarket Solutions

 

You might be surprised by how quickly they reach a temp safe for highway speeds. These aren't cast iron blocks from the 1930s.

But if you're really especially concerned, just stay on the secondary roads a couple more miles and take the next-closest on-ramp instead, at least until you can get a real actual remote starter.

 

Remote start is not going to start the ICE engine. I told you my procedure is not going to help you with remote start. I gave you a procedure for sitting in the car, pushing the start button to put it in ready mode and getting the ICE engine to run for a few minutes to warm it up. I don't think you can do that from the comfort of your home.

KH

 

I live in one of the coldest places on earth, Fraser CO. -20 on many days.
I start the car, let it run for a minute then drive.

Starting the car and letting it run for 15 min is ridiculous

 

Modern ECU controlled, fuel injection engines will compensate; but you still shouldn't drive it like you stole it - right after start-up.