I am a new 2009 owner (1400 miles only) and I saw some of the posts about the gas engine not turning off when you braked. I really know nothing about cars, not technical at all. However, the first couple weeks I had the car it turned off when I came to a stop even just after I got out of my driveway and got down to the first stop sign. Now, this week it seems that for the first couple of stop signs I hit after driving out of my driveway, my engine does not turn off when I totally stop. After about 2 stop signs, then it starts turning off the gas engine when the car is stopped. Should I be concerned? I do not have the AC on in the morning. I did take the car out of town this weekend (but have done that every weekend since I got the car) so maybe with all the highway miles, the battery needs charging and that's what's happening the first couple of stops in the morning?
What you describe is normal. Engine operation varies with temperature, heat or A/C usage, battery SOC, and a few other factors. Cooler weather will require the engine to run more to keep the catalytic converter hot. Tom
+1 on the cold weather factor. The engine will run longer until it is fully warmed up and in cold weather that can take many miles of driving depending upon the conditions (stop & go takes longer).
Yep. Also, the OP should try pressing OFF on the HVAC system to see if the engine shuts off while he's stopped. Then try turning it back on and see if the ICE turns back on. Using the heater can cause the ICE to stay running to provide heat.
I find also even after the engine has warmed up the temperature at which the A/C is set is also a factor.
The engine will run about 30-45 sec. to warm up the cat. converter when you start a cold car (or a car that has been sitting for 5-10 min or longer - actually it goes through this cycle every time you turn it off and then back on). If you have the A/C on "Auto" and it needs to heat the car (temp setting higher than overnight temp) and you are stopped the engine will run until the coolant gets a bit over 62C (the engine will shut off when it's over about 62 but will restart as soon as the coolant drops to 62C). If you watch the battery charge meter, you may notice the engine will run when it's below a certain level. This level has nothing to do with highway or city miles. In order of amount of effect: If you are crawling in traffic (or just crawling to force EV mode) you can drain a battery down enough to force the engine to run. The A/C cooling can drop the battery charge level if the engine is not running (waiting at a light or in traffic for example). If you just sit with the car on (but the engine has shut off), eventually the battery will drain enough that the engine will run to put some more charge in it. Don't worry about any of the above. The car WILL take care of itself. On cold starts (morning for example, but anytime the car has been sitting long enough for the engine to cool off) you will find the maximum fuel economy hit. To reduce this, when you stop to wait for a light, shut off the A/C-Auto mode using the switch on the steering wheel. When the light changes and you start off, switch it back on. Once you have driven 3 or 4 blocks this shouldn't be necessary, as the coolant warms up pretty quickly once you are driving. Don't worry, enjoy your new Prius.
