Acceleration pedal calibration problems ?

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adric22

Well-known member
Joined
Apr 23, 2010
Messages
2,488
Location
Fort Worth, TX
I'm curious if this is a "feature" of the car, or if there is something wrong. I've had the car for several months, but only recently noticed this issue. When getting onto the highway, typically if the on-ramp is on an upward incline, I will depress the throttle a little bit more to give me a little extra power for the climb. Instead of a little bit, I'll get a lot! The power meter on the dash will suddenly jump all the way to the right and I can feel the extra power. All this, despite the fact that the throttle is barely depressed at all. Now unlike the issues with Toyota's, as soon as I release the throttle, the power is also stopped. So it isn't something where I fear I'm going to have an accident or something. But it seems odd.

I theorize that this is possibly designed to do this because I've been driving on the highway a lot more the last couple of weeks for different reasons. Usually I'm driving around in town. Also I usually drive in ECO mode, but if I know I'm going to get on the highway I leave it in "D" mode. I'm wondering if the car recognizes that it is going up-hill and adds extra power to compensate for the climb? It doesn't seem to do this unless I'm going uphill to get on the highway. So maybe I've only recently noticed due to the change in driving conditions?

Anyone else experience this?
 
I would highly recommend starting with the dealer where you bought the car if you thinks it's a real issue. I have not heard of it or experienced what you have described but would be alarmed from the sounds of it.
g
 
i do eco mode all the time. i have on occasion driven in D mode (also happens every time SOC=100%) and it is very responsive.

but as far as sudden acceleration, nothing like that. keep in mind, there is no carb lag on electric motors.
 
If you usually drive in ECO mode, you'll find acceleration in D mode to be much more aggressive. I'd do the test on empty highways several times before I'd be concerned. I tend to think that all that you're experiencing is the normal acceleration of the car, and that the "seat of your pants" is calibrated to ECO mode.

Oh and by the way, I'd like to request that you change the title of this thread to something like "acceleration up hill is stronger than expected". Since you've said that you don't suspect a safety issue and "unintended acceleration" definitely has a technical meaning and has an alarmist emotional component that has caused massive PR trouble for several companies, and since bloggers and reporters patrol this forum looking for stories, I think that the original title of this thread is potentially counter-productive to the public acceptance of EVs.
 
I agree about title change.

I drive in "D" always, and have smoothe acceleration ... but I have only "punched it" a couple of times.

No unexpected surges experienced here.
 
I've found the throttle very non-linear and aggressive in D mode.

It does not take pedal movement at all to induce 60kW+ of power in D mode. It feels like less than half of the travel. I have also noticed that the bubble indicator seems to hit max power before the energy monitor gauge is actually at 80 kW.

In ECO mode I find the pedal to be more predictable, but perhaps overly desensitized.

Going from ECO to D it certainly can take a bit of adjustment to avoid 6+ bubbles - but the car sure feels light in D compared to ECO!

Why can't they just give us a pedal that is pretty much linear?
 
Try driving in D only, for a couple of days, it could be just a matter of perception. I wish Nissan would do something like gradual settings between Eco and D. Right now it is like Driving Ferrari right after driving a glof cart... Sure thing Ferrari would be suddenly accelerating too much :)
if after that acceleration would feel unusual, take the car to the dealer.
 
I'm pretty sure I read somewhere that if you're in Eco mode, the throttle is mapped to give you full power if you stomp it to the floor. This was done deliberately so that even if you're in Eco mode, you have max power available for emergency manoeuvring. I've experienced this in Eco mode, but in Drive, I've found the throttle to be pretty linear.

YMMV... ;)
 
garygid said:
Your "not take pedal movement at all" an "feels like less than half of the travel" ... do not compute. :)
Sure it does. 60 kW+ should take about 3/4 pedal movement - but in D it feels like it takes less than half.
 
adric22 said:
When getting onto the highway, typically if the on-ramp is on an upward incline, I will depress the throttle a little bit more to give me a little extra power for the climb. Instead of a little bit, I'll get a lot! The power meter on the dash will suddenly jump all the way to the right and I can feel the extra power.
It's the normal deal adric. Maximo torque-age these "'lectric" motors have. Cool huh. If it's not your style, use ECO mode and it basically goes away. Me, my ankle gets tired using ECO mode any more but that translates into me being a lucky LEAF owner with only a 34 mile daily freeway commute. It's definitely much different than any ICE car for sure and one can make a fair case that it is too sensitive as you are experiencing (but I still contend it is acting exactly how Nissan designed it to act).

Oh, yeah... definitely recommend changing the title as Boomer suggests. Flips out some world "reporters" looking for an easy negative story when they see this type of thing.

Malcolm :geek:
 
Okay, let me be more clear on this. For those who say I should change the title, I disagree. The car is accelerating more than I intend it to, so it is unintended acceleration. Since nobody else is reporting this issue, let me be more clear. Is there any situation where you would have the pedal pressed only perhaps 1/8 of the way down, yet you see full-bars on the power meter of the dash? Because that is what is happening. I would think for those who are suggesting that I'm just not used to the extra power of "D" mode, I can't agree with that. Because on a straight highway I will have to press the throttle all the way to the floor in order to max out the power reading in either "D" or "ECO" mode.

I'll have to keep my eye on it for the next few days and try to see how often and when it occurs.
 
adric22 said:
Okay, let me be more clear on this. For those who say I should change the title, I disagree. The car is accelerating more than I intend it to, so it is unintended acceleration. Since nobody else is reporting this issue...
...You should take it into the dealer, ASAP. If your car is surging ahead with little pedal input, then something is very wrong with your car.
 
I know people don't want the "stigma" but I've posted about this in the past and the behavior is VERY repeatable on my car.

From a standing start in D aggressively hit the pedal about 75-100% of the way for a second or two then slowly (over the next 3-4 seconds) back off the pedal but only to about 20%. You will see and feel the power meter continue to climb, even as you back off the pedal, to nearly max power. If you mentally note where your foot is (while it's putting out a lot of power), let completely off, which will kill the power, then go back to that position, it will only put out maybe 3 dots.

I rarely drive in D, but I am a leadfoot. If you aren't aggressive on the pedal and don't drive in D you will NEVER feel this. I encourage everyone to follow the steps above and see for yourself. I never did put the logger on to prove it, but it absolutely happens and it's repeatable. It's worth a note that I have a very early car and do not have the newest firmware.
 
davewill said:
adric22 said:
Okay, let me be more clear on this. For those who say I should change the title, I disagree. The car is accelerating more than I intend it to, so it is unintended acceleration. Since nobody else is reporting this issue...
...You should take it into the dealer, ASAP. If your car is surging ahead with little pedal input, then something is very wrong with your car.

Well, I probably "should" but I know this would be very difficult to diagnose in the shop and the technician would first have to drive the car for many miles and also be familiar with the car enough to understand what I'm describing. This is one of those situations where the tech is going to spend a ton of time and because it is all diagnostic work, won't be paid anything. So ultimately he will say there is nothing wrong. That is what I anticipate happening.

However, after seeing turbo2ltr's post right above this, it may turn out to be normal behavior for the car. I don't consider it much of a safety issue being that if I let off the throttle, the acceleration stops. So it isn't like a run-away car scenario.
 
I drove my car in "D" this morning. And though I didn't get on the highway, I was paying very close attention to how the throttle behaves under different scenarios. One thing I've noticed is that the throttle seems to vary not only with how far the pedal is pressed, but with the speed the car is going and the amount of load (for example, going uphill). I wonder if this was done on purpose to better simulate a vehicle with a transmission? I've been driving different models of Prius since 2003 which don't have a traditional gear-shifting transmission so I am totally unused to this behavior.

I suspect this is a firmware issue, and it may be intentional, so taking it to the dealer probably will result in nothing.
 
The conditions you describe in your initial post would seem to be the root issue of your concern.

When driving in ECO the pedal softwre operates in a more "relaxed" mode in the case of acceleeration. When you exceed the the parameters by increasing the amount of rate/amount of acceleration pedal applied; the vehicle responds as by reverting to the "D" mode giving a much more rapid response. It may appear to be unintentional but is a design feature siimilar to the "kickdown mode" on an automatic transmission.

Sometime when you are crusing at a steady speed (in a safe environemnt); hit the pedal and see if the response is similar to what you experience on the ramp.

Keep us informed of your findings.
 
There is nothing wrong with the car. You must be driving in ECO mode. ECO is mapped with a low gain until 1/2 throttle, then it jumps to full power. This is to provide power for driving scenes where full power is desired. "D" is very linear up to 1/2 throttle where it maxes out at full power. Most people do not press the pedal more than half way during normal driving. :geek:
 
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