[Mrgolfer21]

I have a 2019 Hybrid Limited Plat. When it's cold and I need the heater I've noticed it takes a little longer than all my other cars (including a 2008 Highlander Sport). It will usually take a good 10 mins before it starts blowing hot air. When it does, it's all good. When it happened the first few times, I actually thought something was wrong with the heater until it finally kicked in.

Fast forward to this week and the ice storm here in Texas where I live. After spending 3 days locked up in the house, I decided to venture out and cruise around my neighborhood to see how bad the ice was. It was 28 degrees outside and I slid around the neighborhood for 30 mins (gotta test the AWD every once in awhile).

What was concerning was that my heater never started blowing warm air. Keep in mind in my driving around, I never went over 30mph and half the time, I was riding my brakes as I creeped around. Most of the time, other than punching the gas to spin the tires here and there, I was in battery/EQ mode. The temp gauge was in it's normal location (halfway between C and H) within 5 mins. My car is garaged at all times, so it wasn't sitting outside coated in ice or anything. After 30 mins of cold air blowing, I decided to take it outside the neighborhood and drive it faster. I went on one stretch of less icy road about 3/4 mile long and got it up 45mph. Then it started blowing warm air. However, at the stop sign, I needed to turn down a different road that was very icy, so was back to creeping along at 25mph and alas, back to it blowing cold air. 1 mile later, I was able to turn down a different road back towards my house with less ice and again, got up to 45 and it started blowing hot air...and yet again, when I slowed down to turn back into my neighborhood and creep along, cold air came out.

I'm dumbfounded by this. I had the temp on high, and switched around between vents (both floor and face vents) along with defrost. Even with defrost on, my windshield started to get iced up due to it blowing cold air. I feel if I was stuck on a highway going 20 mph for 20 miles, I'd freeze to death. I'm sure we have all done the start the car and sit in it while it warms up/defrosts, but that doesn't seem possible in this car. Is this a huge design flaw where the heater doesn't kick in unless you are driving at a speed where the engine is running generally on gas? I feel like the problem is that I was mostly running on battery when I driving and recharging the battery while riding the brakes and thus, the heater doesn't kick in. But that seems like a pretty bad design. What am I missing?

 

[scipper77]

Sounds like your thermostat is not closing all the way. It should throw a code if you drive for too long without hitting operating temp..

 

[katekebo]

In order to warm up, your engine needs to burn gasoline. When driving slowly in a hybrid, the engine is off for most of the time so it doesn't burn much gasoline and takes a very long time to warm up. Some hybrids have an electric heater to provide extra heat in such situation. My wife's Lexus NX 350h has a "button" on the touchscreen for "fast heat". This turns on the electric heater. I know that some previous generation RAV4s had a similar system. Don't know about the Highlander. Check your Owner's Manual. Usually the Owner's Manual is a better source of information than an Internet forum.

 

[gold94corolla]

Your vehicle isn't in some sort of "eco" mode is it? Eco mode de-prioritizes heat and AC. I don't even bother with the heat in my hybrid, though the seat heater works nice. I have a water temp gauge I installed to see when the temp gets closer to 180° and I know I can run the heat then.

 

[Mrgolfer21]

No eco mode, I've got two buttons where I can turn on EV mode and Eco mode...while I'll turn eco mode on when I'm driving a steady speed down an interstate, I don't have it on at all while in the city. I don't have any other fast heat button that I'm aware of, but will check he manual.

Over the weekend I had a similar episode. Went out to eat, left the house and it was 51 degrees outside. I had the heat on high as I wanted to see how long it took. About 8-10 mins was the time it took to start blowing hot air. The ride back was the most perplexing. I took a few more side roads on the way back, so it took longer. It was 42 degrees out now and the car starting blowing hot air about 7-8 mins into the drive, so all is good. However, as I got close to my neighborhood and started to slow down, the heat switched to blowing cooler air. I turned into my neighborhood and once within the hood, it's 1.5 miles from this entrance to my house. I'm cruising at the posted speed limit of 30 the whole time and it's blowing cool to cold air (like outside air). I have two stop signs I have to stop at, so at both I push on the gas hard to get it to switch out of battery only mode but still nothing. I pull into my garage with it blowing cool air. I put it in park and it clicks off due to the start/stop feature. As most of you probably know, you can't "rev" the engine while in neutral anymore with these cars, but in park, you can push on the gas pedal and it won't throw up a message. So, I sat in my garage in park and pushed on the gas. It didn't start up, but after about 30 seconds, it started blowing hot air. And got pretty hot. Within about 2 mins, it was blowing hot enough air on high that I was getting too warm. So, it blows hot air for awhile, then all of a sudden doesn't for 1.5 miles through the hood, then sits in the garage and starts blowing hot air while in park. Completely baffled. I didn't touch anything in terms of temp or speed of fan or even mode of fan (face, feet, etc).

 

[katekebo]

So, I looked around and it appears that the Highlander Hybrid does NOT have a supplemental electric heater. Which is surprising, because the much cheaper RAV4 does have it. Guess Toyota tried to save a few pennies. Sucks.