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I did a quick search but nothing come up...searched "delayed throttle response", though I guess I could have searched "hesitation", but alas, here I am and hopefully surrounded by some gurus.

I rarely drive my volt on the interstate, but the wife wanted to go to IHOP and the only way to get there is getting on a 70mph speed limit interstate. Anyway, we ate, then we got back on the interstate to go home. There was a Taurus next to me once I merged and it was swerving a bit and I didn't feel comfortable driving beside it and a car behind me. We were going somewhere in the neighborhood of 70...still on all battery power and in sport mode and in L. I didn't floor it, but I gave it a good punch expecting to cruise up to 75-80 without incident....but it sat there at 70 for 2 seconds then "kicked in"....was definitely a hesitation or delayed response, whatever you want to call it...foot down, 1 second, 2 second, there she goes like I originally expected it would. Got ahead of the car and coasted back down to 70 and then I tried to accelerate again to see if it would replicate...it did. Twice more.

Again, I rarely drive on the interstate with this car and do not know if this is normal behavior, but I would have to guess that it's not.

Anyone else have a similar experience?
 

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Two seconds is longer than my usual experience, but the behavior is normal - and mostly only noticeable in sport mode.

The Volt actually has four operating modes - two on gas, and two on electricity:

http://www.youtube.com/watch?v=AX5ZwzNwTc4

At higher speeds on electricity, it connects the second drive motor to the ring gear and drives the ring gear forward with it. This cuts the power consumption by 2-4% - but at a price. The price is the hesitation you felt - the second drive motor has just over half the torque and is fighting adverse gearing - with the result that the car can't accelerate more than ~1/2 throttle while in 2 motor EV.

If you push hard, the car shifts back to single motor EV - but in sport mode you often ask for it faster than the car can stop the ring gear and clutch up to unleash the main motor. The car will wait ~30 seconds at speed to see if high demand is required before shifting to 2 motor - and will do the same thing again after a passing type event.

I mentioned sport mode because in my experience I don't feel it in Normal/Mountain (my 2012 doesn't have Hold.) Obviously the car is still shifting between 1 and 2 motor EV based on conditions, I see that on my DashDAQ - I think that the slower ramp rate of the pedal generally gives the car enough time to shift while you're pushing the pedal down, so that you don't notice the power vacuum.

Occasionally when I'm driving aggressively, I wish I had a "super-sport" mode that would lock out two motor EV and accept the lower efficiency - most of the time I'm ok with the compromise.

In any case, what you're describing is normal, though in my experience not really 2 seconds.
 

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This is like the switch from 2-motor driving to one motor power or acceleration. When cruising along in EV mode, just about anywhere from 35-75mph, if the load is not too high the car will switch to two-motor EV mode which gains it 10-15% more efficiency. However when you want to accelerate hard it switches back to one motor because the second motor make this weaker (but efficient). So its a type of "shift" in modes and takes about 1.5 seconds for it to de-clutch the second motor and reconfure for high-power

It also happens in CS-mode, e.g. see this thread
http://gm-volt.com/2012/02/24/watch...nsmission-shift-gears-in-extended-range-mode/

Here are some more detailed posts for ev-mode
http://gm-volt.com/forum/showthread.php?7575-Simulated-transmission-kick-down

http://gm-volt.com/2010/10/12/chevrolet-volt-electric-drive-propulsion-system-unveiled/

http://gm-volt.com/forum/showthread.php?6611-Voltec-drive-unit-has-four-basic-modes-of-operation

And the videos cited in this are very good
http://gm-volt.com/forum/showthread.php?9139-Chevrolet-Volt-Voltec-Electric-Drive-Propulsion-System
 

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That is "normal" behavior for what you did at the time.

You may have heard that the Volt "occasionally" uses the ICE to help drive the wheels. It does this only at speeds above 35 mph, and only when you are "cruising" at a steady speed. But the Volt also does the same thing with the generator motor at steady speeds over 35 mph, even if the ICE isn't running. They clutch both electric motors to the planetary gear and can then reduce the RPM of the motors, (sort of like an "economy overdrive gear") for about 15% better mileage.

However, when it has changed into the "overdrive" mode, and you step on the throttle, they have to "unclutch" the motors into a neutral, and raise the RPM of the drive motor, then reclutch the drive motor before allowing the car to accelerate harder (to eliminate slipping and wear on the clutches). This is all done by the computer, but takes a second or more, resulting in the "hesitation" you noticed. It's similar to what would happen with an automatic transmission if you had to downshift in order to accelerate hard.

The "cool" thing about this is that because of the computer controlled speed matching and clutch operation, you will get virtually no wear on the clutches, so you get far longer life of the "transaxle" than any ordinary car.
 

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I am constantly amazed by how refined and well thought out the Volt's drivetrain is. Usually, you wouldn't see this level of sophistication until a car had been re-designed over several years of sales.

It is probably the biggest reason the Volt is so "loved" by it's owners.
 

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Here is a lengthy thread started by Jenn last February regarding "Hesitation/Power Loss" in her car:

http://gm-volt.com/forum/showthread.php?30449-Hesitation-Power-Loss&highlight=jenn

I, too, am experiencing this issue and do not consider it in any way 'normal'! In Jenn's case, it turned out to be a defective 'transmission'.

I am trying to replicate this 'throttle lag/tip in' issue reliably so I can demonstrate 'on-demand' the condition to my service department. Only occasionally can I get C268 to 'mess up' when I want it to. Very random.

The one test/exploratory drive I took with my Service Manager, we could not get the Volt to act up. I am seeing less 'lag' incidents as the weather warms up, tho this could just be my imagination. Like xmountaineer, the throttle lag 'usually-but-not-always' occurs as he describes: xway speeds, SM and Low. I had one incident drag-racing down Gratiot Avenue where, when I hit the 'go pedal', the only thing that moved was the "Green Efficiency Ball" in the display ... it scooted up to the top of the graphic while, meanwhile, the Volt was going nowhere, so to speak.

For the few of us who have to put up with this condition, it is not only dangerous but certainly takes some of the fun out the the acceleration event, the Volt EV driving experience that many of us are addicted to and so forth...
 

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I have noticed that when on the highway, L-mode gives a significant delay on acceleration as compared to D mode. I can't tell any difference at slower speeds.
 

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adric22, I'm not sure what you are saying. NORMALLY, there is no delay whatsoever at any speed in any mode in any gear when I punch the accelerator on my Volt. Any "delay on acceleration" is not normal. "Normal" means that the event happens all the time, not just some times. The issue we are describing here is not only random, but very hard to duplicate on demand, at least with my Volt. That is the issue.
 

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I did a quick search but nothing come up...searched "delayed throttle response", though I guess I could have searched "hesitation", but alas, here I am and hopefully surrounded by some gurus.

I rarely drive my volt on the interstate, but the wife wanted to go to IHOP and the only way to get there is getting on a 70mph speed limit interstate. Anyway, we ate, then we got back on the interstate to go home. There was a Taurus next to me once I merged and it was swerving a bit and I didn't feel comfortable driving beside it and a car behind me. We were going somewhere in the neighborhood of 70...still on all battery power and in sport mode and in L. I didn't floor it, but I gave it a good punch expecting to cruise up to 75-80 without incident....but it sat there at 70 for 2 seconds then "kicked in"....was definitely a hesitation or delayed response, whatever you want to call it...foot down, 1 second, 2 second, there she goes like I originally expected it would. Got ahead of the car and coasted back down to 70 and then I tried to accelerate again to see if it would replicate...it did. Twice more.

Again, I rarely drive on the interstate with this car and do not know if this is normal behavior, but I would have to guess that it's not.

Anyone else have a similar experience?
See:
http://gm-volt.com/forum/showthread...ion-on-hard-acceleration&highlight=hesitation
 

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Xmountaineer what you are describing is normal behaviour. My car reacts exactly the same and has since day one. I believe the way the others have described the motor change going on makes pefect sense. The other guy that says his car has hesitation issues that he cannot always reproduce, sounds like he actually may have some sort of issue, but yours sounds like normal operation.
 

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adric22, I'm not sure what you are saying. NORMALLY, there is no delay whatsoever at any speed in any mode in any gear when I punch the accelerator on my Volt. Any "delay on acceleration" is not normal. "Normal" means that the event happens all the time, not just some times. The issue we are describing here is not only random, but very hard to duplicate on demand, at least with my Volt. That is the issue.
Try it out sometime.. Get on the highway in D mode about 65 mph and cruise at that speed for a while. Then really get down on the accelerator pedal and take mental note of the responsiveness. Then put the car in L mode and try the experiment again. I have done this several times. It is repeatable. My wife has even commented the same thing, hence the reason she won't drive in L mode on the highway. There is a distinct lack of instant response in L mode on the highway.
 

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As everyone else has already noted, yes, it happens. It may not be a full 2.0 second delay, but it's gotta be pretty close. Maybe closer to 1.5 seconds. But it sure feels like a long time when it happens.
 

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I agree with xmountaineer, I am always learning something new ever time I read through this web site. Every person here is so knowledgeable and kind, Thanks!!!
 

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As everyone else has already noted, yes, it happens. It may not be a full 2.0 second delay, but it's gotta be pretty close. Maybe closer to 1.5 seconds. But it sure feels like a long time when it happens.
I experienced this on a 16 ELR. Is there fix for this available?
 

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This is a bit like the kick delay noted in another thread. It would seem that the delay is directly connected to where U are when you "kick". if there is electricity the Motor set is the starting point - if not, the engine. Bringing on the 2nd electric or gasoline motor or both take bit of time. I understand the timing implications of a kick are different for each. . As the electric is faster and more powerful - I think - it might be good to have a little power in reserve for that Taurus. That should ensure motor brings on the second motor. Has anyone tried driving in Mountain full time to assure enough reserve power to handle the implications of a down shift burst of power? Little bit like making sure there is enough power for mountains.
 
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