Good Morning All! Anyway, I observed something interesting over the weekend while I was out driving. Anyone else notice this, or have any knowledge on what may have occurred? Before I start, we all pretty much know that the difference between the different modes of driving is essentially pedal sensitivity. There's been talk about it only being the first half of something, but part of me truly still wonders about that. Anyway, I typically would have started this drive out in PWR mode, since I was going to be on the highway, and I prefer the sensitivity of that at highway speeds. However, I was enjoying the weather too much apparently, that I forgot to push the button when I started my drive. As I was approaching (it was about a mile away, I'd estimate) the bridge I had to go over, I pushed the PWR button. It made no difference (If you go from PWR to "NORM" you'll notice a loss of power) until I needed a little more from the engine so I began to gently push the accelerator downwards. The engine gave a smidgen more power, then all of a sudden it surged on me. Imagine a traditional automatic deciding to down-shift to generate that power. Now, I have a cool head, so I let off the pedal, and voila, problem solved. I was traveling around 55 or 60 MPH and for the most part, the road is flat or has some small inclines and declines on it. I was on Rte 13 in Northern DE, before someone asks what road it was. And I travel that route with relative frequency (not daily, but usually weekly or every other week), but I never encountered this event before. Has anyone else had this happen to them after switching INTO PWR mode while already moving? I'm sure there's some criteria that it won't suddenly surge the vehicle ahead the moment you push the PWR button, as we all know the distance the pedal would be depressed in NRML mode would generate more power in PWR mode. Thanks in advance for the replies!
The acc pedal sensitivity is NOT linear, so it depends in what position the pedal was in time you switched to PWR. I'm using this frequently, but always wth pedal in off position momentary.
I don't know the answer to your question, but from a control standpoint it certainly *could* be set up this way. Drive-by-wire control systems use a mapping table or algorithm to determine how much throttle to use for a given accelerator pedal input. Changing the mode to Pwr changes the mapping. The question then becomes "when does the control system do the mapping?" If it is continuous, then changing the mode would cause an immediate change in feel. However, it is equally possible that the mapping lookup occurs only when the accelerator pedal position changes. In this case you would feel no change until you moved the accelerator pedal. Tom
I have noticed the mapping will change immediately when going downwards from PWR > NRML > ECO or any combination as long as you go from PWR towards ECO. However, I believe that it may indeed be that there is no change going the other direction in that you'd receive a sudden increase in power from the ICE. I have done the PWR to NRML several times depending on traffic conditions, volume, and the speed I need to accelerate towards. Holding the pedal consistent (or darn near close) while making the switch definitely decreases the power, and it is therefore required for me to apply more pressure to the pedal. I wonder if anyone else can comment on the mapping setup at all. I wonder if it isn't one of those things you need the software guy to provide the information. Good thing I tend to leave quite a bit of space between myself and the car in front of me. Not that the Prius has "explosive" acceleration, but it could potentially pose a problem if you're driving like you're at the Indy 500 - or around the Washinton DC Beltway because it seems that's typically how they drive there!
I will try this today, I always switch to PWR when I'm moving after the car is warmed up,But when I do I let off of the gas pedal and than back on and it seems be be right there?? I find myself using the PWR mode more and more :nod:
I have noticed this - when you press the PWR button after you are already moving, it doesn't immediately switch into that mode, there is a transition period where the system gradually changes over. You just have to wait for it, and let up on the pedal after you have the power you want.
Yes, try it while still keeping the pedal depressed and let me know what happens. I wonder if I could hook up my SG and have someone watching the numbers - probably not a good idea to do that while I'm driving ;-). I usually drive in Normal, mostly because my typical drive is around town/suburbs in northern DE. I drive mostly 4 - 5 miles each way on a typical drive for me, because everything is so close . But, the 20 mile commute to the local "Farm" store is well worth the trip due to the quality and price of the produce there!
I notice a slight delay when disengaging ECO Mode (so going to normal mode) or going into PWR Mode (either from normal or ECO). It's because of this that I engage PWR Mode BEFORE I need it (e.g. I'll engage it before i enter a left turn lane or early on an onramp)
I find there is a slight delay when pressing power and the system changing. It takes about a second or so. As such, I anticipate this and press the button a while before I need it when over taking or pulling onto a motorway/highway.
When moving from ECO or normal to PWR there is a delay. There is a delay also from ECO to normal. When keeping the accelerator pressed constantly, there is a marked delay. I also think it is not only the mapping of the accelerator sensitivity changing, there is more going on, like the timing of the valves are changed and the algorithms managing the amount of current and fuel going to the motors and how the battery is recharged or used. The changes in behaviour of the car are too extreme in my opinion to just relate the change to a different mapping of the accelerator. Moreover, if you accelerate all the way to the PWR section of the HSI, depending on the mode, you get markedly different accelerations. If the mapping theory was correct, then in PWR section of the HSI, the accelerations would be all the same. Has anybody tried to floor the Prius 3 from 0km/h in the 3 different modes to see if it makes any difference? If the theory of the "gas pedal mapping only" is correct, then it should all be the same. I haven't had a chance to try it yet. The manual says clearly that there is a change in responsiveness, but it does not say how this is done. "Power Mode Use when high levels of response and feeling are desirable, such as when driving in mountainous regions or when overtaking." All on PC have assumed a difference accelerator mapping, based on the chart published on these pages. I personally think there is more to it.
I think that when we look at the HSI, we assume that the bar going across is showing the same amount of power in each mode. I've always felt this to be incorrect, based upon my own experiences. I might actually try to find a place to test, what RPM, etc I can get off the Scan Guage in each mode based upon the HSI display. I may have to wait awhile, though, as it's supposed to rain here the next few days and I'm not too keen about doing that when it's raining outside. Has anyone tried mapping this information? Does anyone have any input as to what information may be good to pull? I"ve only used the SG to disable the reverse & seat belt beeps so far. It's new to me, so I make no promises on what I may actually come up with, lol.
IT SURGES WITHOUT YOU BEING IN THE PWR MODE! It has happened a few times to me now and I've never put it in PWR mode. But my problem wasn't the surge as in changing gear. it is the surge of ICE come on when not expected, meaning that I expected to come on much later than sooner and then just give me this huge boost. Very strange feelings indeed. Defintily not a safty issue but a weird one. Tried to accelerate off fast from the lights, foot very heavy and pressing accelerator hard but car sluggish and not seem to have power 0-25 miles no power for about 30meters and then all of a suddenly bang, a surge forward and then the ICE comes in.
Think of it as the turbos coming on lol. (ok i realise modern turbos are better but I was just trying to be funny)
Maybe it's that new enhancement they made, that causes intended unintended acceleration. And by intended, the car intended for it to happen! Now if only the bumper cars at Cedar Point had a "turbo" right before you nailed the daylights out of someone....
