Yesterday I had to drive into Los Angeles at the start of morning rush hour. I was averaging about 5-20 miles per hour on the freeway and the traction battery was showing fully charged. Yet the ICE never shut off for something like 45 minutes straight.

The FE gauge just kept bouncing within a range of 5-60 mpg, but it never went into the 'E' range at all. And this was with fairly constant throttle input at particular, very-low speed when typically I would be cruising EV for periods of time. Later in the day it went back to normal.

I've never seen this happen before. Could it be some kind of cyclic conditioning of the battery? Does anyone know?

I've noticed mine did this a few times also. I've only owned the car 8 days, so I can't even begin to guess why it would happen. but it annoys me, cause my new form of entertainment on my morning commute is to see how many times I can make the car drop into E mode

was your a/c on? was it in eco mode? not sure if it relates, but i have noticed that at speeds under 39 miles per hour, when a/c is on, the tch tends to keep the ice running instead of goig into ev mode. when i shut the a/c off, it drops right into ev mode.

you know, that could be it? Although it's been downright chilly up here lately (40s) so I haven't had cause to use AC? I'll have to experiment!

I've seen the same thing. You were stuck in Stage 3. To get to Stage 4, so the TCH drops into EV when you lift the throttle (going under 35 miles per hour), you have to stop for 7 to 10 seconds. Just creeping along around 2 or 3 miles per hour for 7 to 10 seconds will also do it.

Your problem was you never dropped under 5 miles per hour long enough to trigger Stage 4. Slowing from ~40mph with the ICE off just leaves you in Stage 3. I often drop the shifter into B if I think the traffic will be stopped long enough to switch to Stage 4. Switching to B will start the ICE up if you are over ~ 20mph.

Edit: remember to switch back to D after the ICE starts!

nyceshirtz Switching to ECO tells the TCH that mileage is the priority. If ECO is off, cabin comfort is the priority and the ICE sometimes will stay running when you expect it to switch off.

Wow. I had no idea about all of the operational algorithms that could come into play.

In fact I did shut off climate control entirely to see if it made a difference. It did not.

Thanks for explaining.

All true, but there is another catch that Nash will probably never see in California that can occur if you live in the cold, cold north. If you "force" Stage 4, and either the catalytic or the heater system is demanding BTU's the car will shut down well enough, but as soon as you start moving in EV mode, it will restart the ICE for warm-up, so you are right back into an ICE "creep" situation with the MGP at 20 or so until you can get up to some sort of speed or until the ECU gets the temps it wants and shuts down the ICE.

Not so sure on this next part, but based on my experience to date, I strongly suspect that the radiator/coolant part of this equation is not based on any particular demand from the environmental system, but is sensed somewhere in the normal coolant circulation.

It is the ignorant among us that will eventually destroy us all.

In cold weather, Motor Trend claimed in its testing of the car the using the ECON button would electrically heat the engine block... thus preventing the need fo rthe gasoline motor to kick on and warm the coolant?

http://www.motortrend.com/roadtests/...ry_engine.html

from motor trend "Among the Camry hybrid's curiosities is an "Eco" button beneath the dash that (among other things) electrically toasts the heater core so the engine isn't required to run for light-duty cockpit warming."

I'll have to go back and check the service manual. I read it that the electric heater is disabled in ECO mode but provides quicker cabin heating when ECO is off. I do notice that if I turn off ECO during cabin warmup the fan speed increases.