Gen3 warming up stages

I measure first bar on 5 min consumption bar. If it's at 10 l/100km => cold night, poor result. If 7.5 l/100km => night about 8 degrees, there is a chance for good normal mode result with low heater penalty.
If about 5.5 l/100km => car is hot (at least +15 deg outside or short break after previous trip) => big chance for 4.7 l/100km for the rest of the trip.

Now I understand why both Auris and Yaris in user's manual had section "Starting vehicle" split between Germany and other countries. After reading it 3 times I found the difference.
In DE - start engine and begin travel immediately. In other countries - start engine, wait for 10 seconds, begin travel.
No startup split found in Prius manual.

 

I am very puzzled by the behavior at start-up of my prius. Rokibler's diagrams are very helpful, and somewhat resemble what I encounter, but still are not quite right. I don't have a scangauge, so I have to go by engine sounds and consumption display.

If the car starts up below 60, it goes into S1a, and follows normal warm-up

If the car starts above 60, even up to high temperatures (i.e. stopped for 3 minutes immediately after 1 hour on the freeway on a hot day), it goes into a strange other stage that doesn't resemble any of the stages described in this thread.

Here are some features of this "stage"
-ICE will only shut off when stopped (resembles S1b)
-when gliding at any speed, the engine will continue to spin at very low rpm's. the instantaneous mpg will show 99 until speed drops <15 mph or so. the energy flow display shows no grey arrow coming out of the ICE. (not S1b)
-cannot press EV mode button (even <10 mph) (resembles S1b)
-doesn't last for a set period of time. If I drive a bit, then am stopped in traffic for a while, it will continue this behavior when the ICE fires again. (resembles S1b)
-happens at a wide range of temperatures, even very hot. (not S1b)
-when this "stage" ends, it goes immediately into stage 4. (not S1b)

So it is similar to stage "4-" that rokibler describes, but it only happens on start-up, and doesn't seem to be temperature- or time-dependent. Additionally, the car never exhibits this behavior at any other time: even if it has been sitting idle for a long time after reaching stage 4, it immediately returns to stage 4.

What is going on?

 

I had this exact thing happen to me about an hour ago. Pretty much just as you described it. The engine was warmed up pretty decent but maybe not fully and I had only shut it off for about a minute.

 

Yesterday I was driving and got "locked" out of ev mode. Guess it was because of heat because none of the other options were valid...

 

@Errantneuron/Markabele - I believe that is called "idle check". Some 10 seconds approx.

 

Hi everyone

With the new design of this forum, the link-backs that were at the bottom of the old design are missing. That is the reason that I make this post, just to tell everyone that wants to know more about the behaviour of the HSD during S1a & S1b stages that there is this thread HSD behaviour during S1a &amp; S1b warming stages | PriusChat

In that thread, for stationary warm-ups you may find several graphs like those below:






I hope you like them

Big hugs from Frank

 

Relative newby: But does the GenIII still have the thermal container to keep the coolant warm? I haven't seen it referenced and some of the postings here suggest cooling overnight, which means they stopped using it. I've looked under the hood and cannot locate anything that would be it.

By the way I posted a backup camera add-on using a 12 volt camera for the 2012 Two on one of the Gen III Accessories blogs. Less than $30 in parts vs over $300 by add-on dealer.

 

Nope.

 

I've noticed a few things that aren't captured in the stages I've seen described - for example, when below 68°C, attempting to glide is a crapshoot as to whether the engine will actually turn off or not - sometimes it will, sometimes it won't, and I don't know if there's an easy way to tell whether it will on a given attempt or not. And then, obviously, above 70°C, it gets to S4, and it's easy to get into a glide. However, something happens in between - once the coolant reaches 68°C, I can glide with nearly 100% success. It's obviously not in full S4 though, because EV is only available to 10 mph. But I've had times where I hit 68°C, then stop for a long stoplight or something, and spend quite a lot of time driving before I hit 70°C, and the behavior is very different from when the temperature is below 68°C.

And, just a tip for anybody that's taking advantage of all this knowledge for hypermiling... The car REALLY likes to turn off the engine at the end of S1b (usually 40°C) and at 68°/70°C. I pay attention as I'm approaching that point so that a pulse brings me up to that temperature, and then I can start a glide right then, since it guarantees the engine will turn off. (If I start accelerating at 38°C and don't start gliding until 42°C, that works too - the engine will always shut off when I stop accelerating after being ready to go into S2. I just try to avoid hitting 40°C right before I need to accelerate, since then the engine will fire back up and keep running for a while.) Then I try to take advantage of the fact that the engine has shut off to go stealth and use only the battery to maintain speed for as long as possible, as long as the SoC is above 60%. I do that because no matter what I do, the car will try to bleed SoC down to 60%, so I might as well use it up with the engine off. If I need to accelerate from a stop, or up a big hill, or some other large power demand, I'll of course use the engine again - but it's almost impossible to get the engine to turn on just briefly for a pulse (like from 30 to 40 mph) when the coolant is between 40° and 68°C - sometimes it works, more often it keeps running. Taking advantage of these known points where the engine will turn off has been fairly handy for me when hypermiling.

 

Can someone please explain what "idle check ceremony" is and why the Prius needs to perform it every time? Aren't "ceremonies" performed only once in a while?

 

Also, are the speeds mentioned in this thread the speeds displayed by ScanGauge or on the dash? The reason I was asking is that the dash is like 3MPH higher than that shown by SG from what I heard. Thanks.

 

I've always felt that 'ceremony' was probably a dictionary translation from the original Japanese of whoever coined the term. My guess is 'procedure' might be a better term. Basically, I think it's the various actions that the car performs and conditions that must be met while the engine is more-or-less idle. I think in the Gen 2, this had to happen while the car was stopped, while the Gen 3 can do it while the car is gliding.

The dash, I believe. Certainly for the EV Mode speed limits, so I'd assume the others are as well.

 

This is the behavior I see as well. But this seems to belie the end point at 103F for end of s1b at which point I should be able to glide if it starts between 25 and 45 MPH. Anything I could be doing wrong to be denied the 25-45 MPH glide?

 

I think we all see this behavior from time to time. A couple of things you may already be aware of, the ICE will not shut down if the catalytic converter is not hot enough, another thing that will keep it running is the heater trying to warm up the interior.

 

I was aware of the latter but not the former. Which makes me wonder if certain gas brands could cause ICE/Cat to heat up sooner. I seemed to notice better MPG with Shell "Nitrogen-enriched" fuel. But I am not sure if that's the reason or my fluctuating driving style.

 

It is great when you get the technical description that fits what the car is doing. I love the way the car pulls away from a cold start. Where I park the car at work there is a slight uphill grade so as long as you don't put you foot down too much the car pulls off with the engine doing constant rpm and the car smoothly accelerating away, with more power than you would normally be allowed to take from the battery. At home there is a short steep rise but now that I know what it is trying to do, I don't use too much throttle and the car stays in stage 1 warmup. Coldest temp recorded this winter has been 4 degrees centigrade and I think the car warms up faster if you let it do what it wants to do. Warmup is measured by the car allowing gliding sooner and the heater providing heat sooner.

 

We have a 2013 Ford Fusion Hybrid and are considering a Prius as our second car. The Fusion Hybrid follows these same steps almost exactly only with different temperature triggers. My question in the Prius is: is there a way to skip S1a and force the Prius into S1b? I have learned how to do this in our FFH and it contributes to our averaging 55 MPG in a car rated 47 MPG without any hypermiling techniques. Thank you!

 

New observation from my Prius Gen III, 2011 with recent IGBT firmware patch, European.

1) Car parked for 4 consecutive days
2) Outside temperature ~ 10 Celsius
3) Battery SoC 57 - 61% (happened few times in this range)
4) Internal temperature target: AUTO, +18 C, A/C OFF
5) Actual internal temperature: +16 C
6) ECO Mode

I entered my car. Started as usual, but due to two longer stays I attached Torque to OBD to read Aux Battery voltage (11.7V in IG-ON).

Engine coolant temp went from 10C up to 55C then engine shut off with SoC at about 60.4%. I was in very bad stop & go traffic (more stop than go for few minutes). I was observing engine coolant as it was slowly going down.
I was pretty sure that it will restart ICE at 52C. But temp was still going down. After all it felt down as low as 39C. Then ICE kicked in and warmed up again to 55 C.

Because internal temperature was slowly rising and road conditions were still very bad I was standing still for another few minutes. SoC went down to 57.4% and again ICE Coolant was getting lower and lower and ICE kicked in again at 39 degree Celsius.

It is quite unusual behavior for my Prius. I never observed it before. It always kicked in at about 52C with fan/heating set to AUTO, except when it was cooling the car (which was not the case because air outlets was set to windscreen/legs by AUTO. When cooling it sets vents to face).

I'm not sure if it's just because I've never observed it before or it has changed with recent IGBT recall.
Or maybe it was just small difference between target temperature and real internal temperature.

 

Greetings,

I have a question about Prius warm up:
If i understand it right Prius starts in EV mode then after short time turns ICE on to warm it up then after some time it starts using EV again. so can it be said ICE is warmed up when car starts using EV mode?

 

Yes, when ice is warming up, the car uses mostly electric power. That's why the battery goes down quickly during warm up