I have had my TCH for about 3 weeks now and I love it. I live outside of Pittsburgh and it has been quite cold here. I have been used to the ICE motor running until the temperature gauge gets in the middle but today was different.

Today it was about 45 degrees F and I pulled out of my parking lot from work. I went about .5 miles and was stopped at a light for about 5 minutes (long light due to construction). The TCH kicked into EV mode while the temp gauge reported just over the "C" reading. I watched it while I was sitting at the light and the temp gauge went all the way down to its minimum setting (below C), but the ICE never kicked on to warm the converter or anything. I should mention that I did not have the heat on either.

I found it kind of odd since I am used to the ICE being on during the cooler temps to warm everything up. The ICE did kick in as expected when I began accelerating after the light changed.

I am certainly not complaining about not burning gas while sitting still but is this normal for the TCH when cold? I always thought the first thing the car would do was warm itself up to operating temperature before kicking into "EV".

The ICE will kick in at certain times, even when it is warm depending on the battery charge level mostly. If the battey level drops or the engine is cold, the ICE will turn on until the battery charge level or the ICE temp is in the normal operating range. You can check this forum and search for more info on this because i know it has been covered many times before.

I understand the ICE would kick on when warm for batery charging and what not, but my experience was the the ICE was not at normal operating temperature at which point I would have expected ICE to run to get the temperature up to that level.

So the car was not at normal operating temperature and the car did not make any effort to get it there either, which I found strange.

I've found that mine will shut off before getting completely warmed up providing the climate control system is turned off.

Are you sure you have the heater off in both cases?
Speaking of Prius, the engine stops at the coolant is above 40C(104F) when heater off, and the engine continues to run until coolant is 65C(149F) when heater is on.
I believe TCH does the same thing.

Ken@Japan

I'm in the Twin Cities and had the same thing happen this week as we finally had our 4 month long cold spell snap. The key for me appears to be having the heater off. If I leave the heater on, the ICE will stay on. I picked this tip up on another thread.

Does it matter is the ECO mode is on or off?

To some extent, yes.

There was a long thread going on about the TCH's stages and what not. I think there might be some posts on it in the FAQ comments thread as well.

As Mike just noted there are other threads on the impact of the ECO mode. I typically have it on, but the past couple of mornings it was off, and the ICE kicked of even though the temp indicator was only about 1/4 of the way up.

Ok, it appears that having the climate control off holds some key to this. It was warm enough in the car when I pulled out that I did not use the CC system, so that must have had something to do with it.

Thanks for the responses.