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Discussion Starter · #1 ·
Hi!
Just purchased a used 2016 Volt and it's great. But I've noticed when it's in Hold Mode or even more so when the battery is completely depleted and I'm forced to use gas, I've noticed the loss of power a bit as if it's in too high of a gear sometimes. It's the equivalent feeling of if you were driving stick shift and you threw it into 5th gear at 20mph when you should be in 3rd gear. There power falls back and the there's a bit of a revving of the engine as the car accelerates back up into a nice quiet ride. One time on a mountain uphill in all gas mode I was going about 70mph and all of a sudden the power fell away and it was sort of revving and I couldn't get any power. The car slowed to about 55mph and I moved over to the right lane. No warning signs or anything. I even moved it into L gear which did nothing, then I moved it back to Drive. We hit the top of the hill and coasted down and within 15 seconds I hit the gas and the power was back like nothing. I don't know cars much but is that the transmission? Now that issue on the mountain/large hill hasn't happened since and I've driven that road about 10 times since, but it was a bit scary. And on normal every day rides I feel the car sort of "slip" and power is reduced as if it's not in the right gear. It's not like it's going from say 3rd gear down to a lower gear and the car is revving that way, it's the opposite...as if you're in 3rd gear and move it to 6th gear and the car slows a bit and you don't have that power momentarily until it catches up. It's subtle usually but I can feel it for sure.

Not sure if this is normal performance for the non-battery driving. Is it? Or if not, what do you think the issue is? I brought it into the Chevy Dealer after the mountain issue and they did a bunch of "software updates" on little recalls or something like that, one related to transmission, so they said "that might fix it". But it didn't. Still happens. Nothing as extreme as that one large hill issue, but a subtle slip or loss in power on normal gas-only driving every day.

Hope this makes sense. Sorry to be a bit wordy but it's hard to describe. I think the stick shift feeling is the best way to describe it if you've ever driven stick and know what it feels like to be going 20mph and throw it into 5th gear when you should be in 3rd. It drives but there's no power really as your car kind of "catches up" to the speed it should be.

Thanks for your thoughts/suggestions.
 

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Two thing here. First, in hold mode, you can it and the gas engine could have a mind of its own, either barely running when moving fast, or running like crazy when hardly moving at all. That's just the design of the car. Sometimes the gas engine is trying to catch up to the energy that you spent. Next, accelerating from 0-30 can be invigorating, but 30-60 is anemic, because the volt is an economy car and doesn't have ludicrous mode that the top Tesla has.

Now the mountain issues. Were you in mountain mode or normal mode when attempting this? If you were in normal mode, and you tried to go up a big mountain on a depleted battery, it would restrict your acceleration uphill to keep you from dangerously daring the battery below it's lower limit. So t that point you are spending energy created by the ICE pushing the generator, and no more. When you started going downhill, regen gave the battery enough juice to allow you to climb the next hill.

So if this was what happened, the way to prevent it is to get into mountain mode before you hit the mountains. This causes the ICE to keep a buffer of electricity in the battery to help avoid these power lulls.
 

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On your long uphill you ran out of battery charge so only the gas engine powered generator was available to drive the car. The generator output is not enough to maintain high speed up hill without battery help. That is what mountain Mode is designed to avoid. On gas the power flow during cruise is partially direct mechanical drive and until it shifts out of this state when flooring the pedal it may well be sluggish feeling. Perhaps your car is stuck in this hybrid state when it should shift to all electric.
 

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Discussion Starter · #4 ·
Two thing here. First, in hold mode, you can it and the gas engine could have a mind of its own, either barely running when moving fast, or running like crazy when hardly moving at all. That's just the design of the car. Sometimes the gas engine is trying to catch up to the energy that you spent. Next, accelerating from 0-30 can be invigorating, but 30-60 is anemic, because the volt is an economy car and doesn't have ludicrous mode that the top Tesla has.

Now the mountain issues. Were you in mountain mode or normal mode when attempting this? If you were in normal mode, and you tried to go up a big mountain on a depleted battery, it would restrict your acceleration uphill to keep you from dangerously daring the battery below it's lower limit. So t that point you are spending energy created by the ICE pushing the generator, and no more. When you started going downhill, regen gave the battery enough juice to allow you to climb the next hill.

So if this was what happened, the way to prevent it is to get into mountain mode before you hit the mountains. This causes the ICE to keep a buffer of electricity in the battery to help avoid these power lulls.
I was in Normal mode going up the mountain. Well, really big hill anyway. One that takes a good 3 minutes to climb at 70mph. I hadn't had any battery left for like 50 miles after that long drive. I was just cruising up the hill like normal. And yeah, it doesn't fly like my old V6 Solara did, but it was just...normal. Then suddenly without warning 3/4 of the way up it just turned and lost power, I could push the pedal to the floor and there was about 10% of the power you'd normally get. I had the pedal to the floor pretty much but watched as the speed went from 70's to 60's to 50's without the ability to accelerate any more. Had I been at the bottom of the hill, I'm not sure I would have made it to the top. That, to me, isn't normal. Even for an economy car. Most economy cars hit big hills and there's not much acceleration or power, and the rpm's are going high to get enough power to climb the hill, but it never drops off a cliff power-wise. This can't be normal.

Or is it?

This mountain issue happened once. A month ago. So I don't wanna get hung up on that (although I wish I knew what caused it because pushing the pedal to the floor and having the only have 10% of its normal power and hearing the engine revving like it's slipped out of gear is unsettling).

... But the daily gas-only feeling like I'm in the wrong gear seems odd to me. Like worse performance than a low end economy car. It's almost like not enough RPM's are happening because the car shifts into too high of a gear. I drive long distances in this car so inevitably I end up in gas-only mode quite a bit. Do you experience the same sort of feeling with this car when the battery is depleted? (and even when you're in hold mode to some extent?)
 

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Discussion Starter · #5 ·
On your long uphill you ran out of battery charge so only the gas engine powered generator was available to drive the car. The generator output is not enough to maintain high speed up hill without battery help. That is what mountain Mode is designed to avoid. On gas the power flow during cruise is partially direct mechanical drive and until it shifts out of this state when flooring the pedal it may well be sluggish feeling. Perhaps your car is stuck in this hybrid state when it should shift to all electric.
Yeah, unfortunately, some of my drives are like 150 miles so my battery is gone and there's nothing I can do so Mtn Mode isn't an option. But as I described in my last response just before this one to the other post, I can't believe this would be normal. So does everyone experience the issue or sensation of the car randomly revving as if it's slipped out of gear while driving in gas-only mode? The mountain experience was an extreme case where I lost all but maybe 10% of my power on the hill. As in, (like I said in my other response), I was going up the hill at normal freeway speeds then suddenly something changed and the engine revved and I lost all power at once (except maybe 10%) so that even when I floored it my speed was decreasing from 75mph to 50mph in a matter of 10-15 seconds with no way to stop it. It went from normal feeling to helpless in an instant. That can't be normal. Again, it's like it slipped out of gear entirely. And the day to day sensation I feel can't be normal either. I've driven many crappy older budget cars, and yeah, they don't have a ton of power at all, but they don't feel like this.

Neither post said there might be an issue, which is fascinating and somewhat disheartening to me. I figured there must be something wrong. I almost wanna go to a dealer and test drive one in Hold mode on a 10 mile freeway stretch to see if I feel the same issues.
 

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Yeah, unfortunately, some of my drives are like 150 miles so my battery is gone and there's nothing I can do so Mtn Mode isn't an option.
Of course mountain mode is available, simply engage it ~15-20 minutes before your climb (it doesn't matter if your battery is depleted)
It will run the generator a bit harder in order to generate and bank some energy back into the battery so that when you get to the climb it will be able to have sufficient power reserve for cresting the climb. Afterwards, you can turn it off if you wish.

Welcome to gm-colt.com
WopOnTour
 

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I have a 2016 Volt and it sounds like something isn't working properly.

We have some hills here locally that can be somewhat steep (but not as long). One hill, about a mile long, is steep enough that smaller cars can't maintain the 50 mph speed limit. In the Volt, I was climbing at 50 mph (in HOLD mode), and just decided to try flooring it. The engine revved and my speed increased to 65 mph and could have gone more, but I backed off.

The Volt's engine has 100 hp, so it should not have the problems you are mentioning. Maybe it is a transmission problem and you aren't getting the engine to rev as required. I suggest you have it checked out with a tech on board during a test drive.
 

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To further emphasize what WOT said: Available battery charge is required for optimal performance in hilly terrain. That's what Mountain Mode is designed to provide, but you have to switch to it well before starting your climb, then switch back to Normal Mode when you start climbing. RTFM.
 

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To further emphasize what WOT said: Available battery charge is required for optimal performance in hilly terrain. That's what Mountain Mode is designed to provide, but you have to switch to it well before starting your climb, then switch back to Normal Mode when you start climbing. RTFM.
If you really read the manual, you'll see it says nothing about switching back to Normal when you start climbing. You stay in Mountain the entire time you are in mountains (climbing).

I only have the 2013 manual, I imagine 2016 isn't too different:

9-3
Use Mountain Mode prior to climbing long, steep grades in mountainous areas. Be sure to engage Mountain Mode before starting to climb. Mountain Mode reduces electric range and power but may be needed to maintain speeds above 96 km/h (60 mph) when climbing grades of 5% or greater.


Are you certain you didn't get a "propulsion power is reduced message"? That is the exact scenario you describe, so the car should have popped that up. Please learn about Mountain mode, it's there for exactly the reason you had a problem, and it will fix that problem.

5-49
PROPULSION POWER IS REDUCED
This message displays when the propulsion power is reduced and can affect the ability to accelerate. If this message is on, but there is no reduction in performance, proceed to your destination. The performance may be reduced the next time the vehicle is driven. The vehicle may be driven at a reduced speed while this message is on, but maximum acceleration and speed may be reduced. If this message stays on when the malfunction
indicator lamp is on, the vehicle should be taken to your dealer for service as soon as possible. This message can display when driving in mountainous terrain without using Mountain Mode or by not entering Mountain Mode soon
enough to build a sufficient battery charge reserve before climbing steep grades. This is normal operation to protect the high voltage battery. Only if both the PROPULSION POWER IS REDUCED message and the malfunction indicator lamp are on should the vehicle be taken to the dealer for service. While climbing the grade with this
message displayed, the vehicle speed may be reduced until the engine can recover the battery state of charge to a normal level



Now your day-to-day issue, I can only say my 2013 never feels like that, but the 2016 has a slightly different transmission. I'll defer to other 2016-17 owners for that, but I'd be surprised if that is normal.

Edit: after re-reading your day-to-day issue, I am wondering... do you not feel enough power, or is it just that the weird/crazy engine revving is bothering you? Keep in mind that the Volt is really an "electronic CVT" (eCVT), so at 30mph the engine can be going anywhere from 0 rpm to redline, regardless of what power you are requesting. This is weird at first, but note that most of your power is still coming from the electric motors and performance should not be any different than when on pure battery (ignore the revving and punch the throttle and see). Many Volt owners try to only use the engine on the highway, using Hold to preserve some battery for around town driving at their destination. I do that, I don't like the engine on at slow town speeds, partially because silent EV drive is more noticeable and fun at low speeds. At highway speeds, the engine doing its eCVT thing is much less noticeable because of higher road/wind noise and it doesn't bother me. Give it a try.
 

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This is why many Volt owners refer to their cars as EREV's and not hybrids. The real power in a Volt is the electric motor. It's more powerful than the gas generator.

The only other EREV that is more powerful in electric mode than gas is the i3 Rex. However, in the situation you encountered, you'd be going 25mph up that grade. The engine in the BMW is a 2 cyl motorcycle engine with about 25kW of power.

Here's how your car work:
The battery is never empty. There is always room at the top of the charge window, and the bottom of the charge window (depleted). Lithium batteries do not survive long if you charge them to 100% (4.2v) or drain them to 2.0v a cell. So there is a protection window. Then there is a second window that you actually dip into. On the top, there is a window to allow your Regeneration to work correctly when the battery is fully charged, and a bottom window to keep 120kW on tap with the 75kW ICE running. Yes, when the ICE puts out only 101hp, and the charge is zero, and you floor it, it kicks out 161hp still by using the buffer. But the buffer only holds a couple miles in it, then it reports REDUCED POWER and cuts you back to UNDER 101hp so it can start to slowly build back up a charger in the buffer.

55mph is a safe speed, but that must have been confusing. Next time use mountain mode early. It won't even come on until the battery is fairly low. It just maintains a larger buffer on the bottom. You can use HOLD to make even a bigger buffer.

It is the Achilles Heel tradeoff for going Big EV, Little ICE, but I think they balanced it better than BMW did.

It is interesting to note there is grade south of Santa Barbara on the 101, steep but not too long. I had in it HOLD mode, and I was following a New Prius at 80 mph before we hit the hill. I had 3 adults in the car. 1/2 way up (not far), his speed started to fall. We kept up our 80mph and passed him to the right. Hybrids have that same buffer, and the 121hp Toyota prints, only applies when the buffer is full. Their buffer is much small though.
 

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If you really read the manual, you'll see it says nothing about switching back to Normal when you start climbing. You stay in Mountain the entire time you are in mountains (climbing).
mea culpa. I guess I was remembering the following from page 9-24: "While driving in Mountain Mode, the vehicle will have less responsive acceleration." You should probably only shift out of Mountain and back to Normal mode if the climb will be short in duration and not exhaust the battery charge reserve. I think I'm going to go back and RTFM myself.
 

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Of course mountain mode is available, simply engage it ~15-20 minutes before your climb (it doesn't matter is your battery is depleted)
It will run the generator a bit harder in order to generate and bank some energy back into the battery so that when you get to the climb it will be able to have sufficient power reserve for cresting the climb. Afterwards, you can turn it off if you wish.

Welcome to gm-colt.com
WopOnTour

That is why it is STRONGLY RECOMMENDED TO KNOW AHEAD OF TIME that you are going to cross some mountainous terrain on a long trip. Even on short trips. Know thy mountain ranges... Then set your Volt to mountain mode as recommended by WopOnTour. I have no trouble passing through Tejon Pass going up at 75 mph. I go down the steep grade and recovered many of my electrons.
 

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mea culpa. I guess I was remembering the following from page 9-24: "While driving in Mountain Mode, the vehicle will have less responsive acceleration." You should probably only shift out of Mountain and back to Normal mode if the climb will be short in duration and not exhaust the battery charge reserve. I think I'm going to go back and RTFM myself.
To be fair, the manual could be more clear. And I do think some people do what you say: use Mountain to build up a reserve and then switch to Normal during the climb (if it's a single climb and they know they have enough reserve to make it up) because it is more responsive. I live in a non-mountainous region so I've never had to play with these options.
 

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Since 2013, I've only seen the Reduced Power once. Then I figured out how to work with the buffer.

Once you understand the battery buffer, it will become second nature to use Mountain or Hold for long trips that exceed the EV range.

Your EV power is most efficient at 60mph and lower, and your gas generator (ICE) works best at the higher speeds. If I need to go 150 miles, I wait until I'm going to be going steady at 65mph or higher. Then I hit Hold and drive any speed I want. Say that's 3/4 charge level. When I get 40 mile away from my destination, I push the button once to end up in Normal, and finish the trip. I get to my destination at full speed, with 0 battery left. If I do it PERFECT, it arrives on EV power with 1 mile or 0 mile indicated. It's a game I like to play.
 

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The OP is driving a 2016 Volt. The MM-maintained battery buffer for the Gen 2 Volts has been reduced to ~2 bars of power from the Gen 1's ~4 bars. With a more powerful ICE output, there’s less need for borrowing power from the battery. Fewer driving conditions exist where that might happen, and when and if they are encountered, less additional help from the battery would be needed. It’s unclear if the MM buffer is still needed for the Gen 2 for "driving up steep hills" purposes, or if it was kept because owners would expect it to be there. I don’t think I’ve previously read of any Gen 2 driver reporting Reduced Propulsion problems because Mountain Mode had not been engaged, but I have read one posting of a California driver successfully driving a Gen 2 through the Grapevine without using MM.

The OP did not report any Reduced Propulsion message, although it might have appeared and gone away without being noticed. Is it possible he’s experiencing the "chuggle?"
 

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Discussion Starter · #16 ·
Of course mountain mode is available, simply engage it ~15-20 minutes before your climb (it doesn't matter is your battery is depleted)
It will run the generator a bit harder in order to generate and bank some energy back into the battery so that when you get to the climb it will be able to have sufficient power reserve for cresting the climb. Afterwards, you can turn it off if you wish.

Welcome to gm-colt.com
WopOnTour
Thank you so much for (all) your response(s)! I did RTFM but I didn't totally UI (understand it...yeah, I just made that up). I know tech, but A/V tech, so knowing the ins and outs of cars is new but fascinating enough that I dropped 25k on a lightly used car (mostly cuz it had the sticker :)

Okay, I'm gonna respond to each post if needed. Here's my response to this post...

If you all know SoCal, I was heading up the 241 from the 91 freeway towards the 5 freeway when the "bottom fell out" of my power suddenly. I had driven tons already (I often drive 100 miles for work) and hadn't charged the night before. Life happens. Anyway, when I started that drive I was leaving a place about 3 miles away from the large hill (not exactly a mountain), my battery was already at 0 miles. I guess I could have still put it into Mountain Mode, but I had sufficient sustained power on gas through my drive up to that point. Yes, you can feel it working hard to get up that big hill but nothing crazy, and yes I was going 75, traffic speeds, no big deal. Then in an instant 90% of the power dropped out and it sounded like I was out of gear. I looked at the dash for any messages, none. I looked all around for an answer to no avail. I dropped it into L with no change, then back to D. I pushed harder on the accelerator because at this point the car was dropping speed below what others were driving at. I moved to the right lane and by the top of the hill I was around 50mph or so. Then went down the hill and all was normal again. This was a one time event. The day to day feel is less dramatic for sure, but more annoying because it's every single day in HOLD (when I still have battery miles remaining) and also when I'm out of battery and am driving in Normal on flat freeways everywhere in SoCal.
 

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Discussion Starter · #17 ·
I have a 2016 Volt and it sounds like something isn't working properly.

We have some hills here locally that can be somewhat steep (but not as long). One hill, about a mile long, is steep enough that smaller cars can't maintain the 50 mph speed limit. In the Volt, I was climbing at 50 mph (in HOLD mode), and just decided to try flooring it. The engine revved and my speed increased to 65 mph and could have gone more, but I backed off.

The Volt's engine has 100 hp, so it should not have the problems you are mentioning. Maybe it is a transmission problem and you aren't getting the engine to rev as required. I suggest you have it checked out with a tech on board during a test drive.
Thank you for your response. Interestingly you are the only one to say this. This is what I suspected users to say but most are focused on the big mountain/hill issue that I experienced once. Which I do appreciate. But again, the day to day revving (as if it's slipping into gear as described before) on normal flat freeways around SoCal is what's the biggest annoyance for sure since it's every single day (yes, I use HOLD mode on freeways and Normal on streets, and Sport when my son is in the car and he says "Go super speed daddy" :)
 

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Discussion Starter · #18 ·
To further emphasize what WOT said: Available battery charge is required for optimal performance in hilly terrain. That's what Mountain Mode is designed to provide, but you have to switch to it well before starting your climb, then switch back to Normal Mode when you start climbing. RTFM.
Thank you for your post. As I mentioned two posts ago in my response, my battery was done. And I was just leaving a place a couple miles from this hill. I'll try mountain mode next time but again, my biggest annoyance is the every day issue on flat freeways in HOLD mode (or in Normal Mode when the battery is depleted) as it has the slipping sensation as I accelerate as if you're in 3rd gear and you skipped 4th gear and went to 5th or 6th. It's the opposite feeling of downshifting. Hard to describe. Sorry. And like I said, I did RTFM, but I didn't UI. Not entirely anyway. The forums and posts have helped since. The mountain/hill issue was a one time dramatic thing, but the day to day issue is my biggest concern.
 

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Discussion Starter · #19 ·
Okay, so without repeating myself too much because there are a lot of posts (thank you!!!!) I'll say this...

I do drive on freeways here in SoCal in HOLD mode when going fast. And normal mode on streets. I do play the game to try to make it home sometimes with 1 mile of battery power left. I've only had the car for 2 months but I love it. I had a squeaky break pedal that was annoying but now it's fixed but this issue remains. The hill issue (again for those of you in SoCal it was the 241 between the 91 and the 5...nothing crazy like a real mountain but a serious hill) has happened only once. I've driven back and forth on that in Hold mode and in mountain mode probably 10 times since with no issue. It was dramatic and a touch scary. No warnings or messages on the display. Switching gears didn't change anything (although you'd think throwing it into L at 60mph would do something, but no change at all). But again, on a day to day basis when I'm on the freeway going 65mph like a good boy, and I accelerate in HOLD mode or with the battery gone and in normal, but gas only, the car revs and then "settles" into it's power and I can accelerate like normal and the revving subsides even if I'm still pressing the pedal and accelerating at a steady pace. It doesn't feel right to me. So I thought it'd be a transmission issue. Only one or two posts have said that it might be an issue, and the rest are geared towards how to drive or what to expect, but yet I haven't read "that happens to me too" from anyone which makes me believe there is an issue. If people were saying "that happens to me" I'd know it's a function of the car. But without being able to drive someone elses 2nd gen volt with a depleted battery I can't tell. I plan to go to a Chevy Dealer with 0 EV miles left and take them for a ride on the freeway. In EV mode, the car is great. And in gas mode or HOLD mode, there's power there, it just feels like it slips into gear (or maybe I should say it "settles" into gear) instead of a nice steady ramping of power.
 

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Discussion Starter · #20 ·
The OP is driving a 2016 Volt. The MM-maintained battery buffer for the Gen 2 Volts has been reduced to ~2 bars of power from the Gen 1's ~4 bars. With a more powerful ICE output, there’s less need for borrowing power from the battery. Fewer driving conditions exist where that might happen, and when and if they are encountered, less additional help from the battery would be needed. It’s unclear if the MM buffer is still needed for the Gen 2 for "driving up steep hills" purposes, or if it was kept because owners would expect it to be there. I don’t think I’ve previously read of any Gen 2 driver reporting Reduced Propulsion problems because Mountain Mode had not been engaged, but I have read one posting of a California driver successfully driving a Gen 2 through the Grapevine without using MM.

The OP did not report any Reduced Propulsion message, although it might have appeared and gone away without being noticed. Is it possible he’s experiencing the "chuggle?"
No message. And I looked immediately and looked several times. If it popped up it disappered quickly because this particular ordeal lasted a good 20-30 seconds as I tried to figure out what was up (see my previous few posts that I just made).

Not sure what the chuggle is but sounds not-so-fun.
 
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