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I have had the car about a week now and have noticed some inconsistencies when it comes to using the paddle to brake. Up until today it has been pretty aggressive, all of a sudden it's super gentle and now slowing me quickly at all. Is that normal? That seems pretty weird.

I just feel like it's driving differently all of a sudden, slower maybe? Kinda odd

Second, when using ACC, does that only use the Regen braking or will it apply the friction brakes? I have only used it in my commute a couple times now and once it started beeping because it wasn't going to stop in time in stop and go traffic.

Also... I have had an issue randomly with the acc on occasion where it just won't engage, no matter what. I learned about the brake trick where you pull up on the pedal and then it works. Is that common for the 2017's?
 
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My experience with the regen braking paddle is that initially it doesn't slow the car down much at all but if held in for more than a few seconds deceleration is increased significantly. I'm still trying to get a feel for it as I find myself applying it too early and having to let up several times in order to stop where I intend to.

As for ACC I cannot speak to that as I do not have it. However it was my understanding ACC is not intended for stop and go traffic.
 

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My regen paddle does the same - about 80% of the time it's aggressive but the remaining time it's barely noticeable. I haven't seen rhyme or reason for this but I suspect it has to do with SOC and high voltage electronics temperature.

The brake pedal issue is a documented TSB - some of the 2017s have a faulty or improperly positioned brake pedal sensor that keeps the cruise control from engaging. Lifting the brake pedal "fixes" this. Let your dealership know about this as it's apparently a relatively easy repair and will be under the B2B warranty.
 

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As for ACC I cannot speak to that as I do not have it. However it was my understanding ACC is not intended for stop and go traffic.
Why would that be the case? Isn't that exactly what it's for?
 

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I have had the car about a week now and have noticed some inconsistencies when it comes to using the paddle to brake. Up until today it has been pretty aggressive, all of a sudden it's super gentle and now slowing me quickly at all. Is that normal? That seems pretty weird.

I just feel like it's driving differently all of a sudden, slower maybe? Kinda odd

Second, when using ACC, does that only use the Regen braking or will it apply the friction brakes? I have only used it in my commute a couple times now and once it started beeping because it wasn't going to stop in time in stop and go traffic.

Also... I have had an issue randomly with the acc on occasion where it just won't engage, no matter what. I learned about the brake trick where you pull up on the pedal and then it works. Is that common for the 2017's?
The amount of regen applied by the paddle or brake pedal may be reduced depending on speed and also the battery SOC. If the battery is at ~100% SOC then the amount of regen is limited.

ACC will work in D or L and uses the Volt's blended braking system with regen and friction braking as required.


ACC should not normally trigger the forward collision alert system unless the vehicle/traffic ahead of you slows and stops so abruptly that the ACC does not have time to slow the Volt. Try setting the ACC follow distance to the middle or longer distance setting, not the closer setting. Be aware that for ACC to work the vehicle in front of the Volt must be moving. If you see a little green vehicle symbol in the driver information display when ACC is active then the ACC radar has locked on to the vehicle ahead. If not, then you will need to slow or stop the Volt.

The ACC problem you noted requires the dealer to replace the Volt's brake pedal retainer clip. There is a TSB and this should be covered under the 36 month BTB warranty. What is the mileage on your 2017? Consult dealer for repair.
 
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Why would that be the case? Isn't that exactly what it's for?
That's not my understanding. If it were then one would be able to enable ACC below 15MPH and a warning, using stop and go traffic, is specifically given in the owners manual. Cruise control is intended for open road travel where the need to adjust speed is minimal. ACC improves on that concept. That ACC could be used for stop and go traffic does not mean it was intended for that use case.
 

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That's not my understanding. If it were then one would be able to enable ACC below 15MPH and a warning, using stop and go traffic, is specifically given in the owners manual. Cruise control is intended for open road travel where the need to adjust speed is minimal. ACC improves on that concept. That ACC could be used for stop and go traffic does not mean it was intended for that use case.
I have ACC in my 2017 Volt and use ACC most days, most of the time for local driving at speeds under 40 mph. You need to be traveling at a minimum of 15 mph to engage ACC on the Volt. The Volt will maintain the speed you select and also maintain a safe distance of 1.5 seconds (close follow distance), 2 seconds (middle follow distance) and 2.5 seconds (longer follow distance) from a moving vehicle that is in your lane. Once the ACC radar locks on to the vehicle ahead there is a green vehicle symbol displayed in the driver console. Unless the vehicle ahead suddenly panic stops the Volt will maintain a safe distance from the vehicle including slowing to a complete stop. Once traffic resumes moving you can tap the resume button or the accelerator pedal and the Volt will start to move forward under ACC. In a panic stop situation ACC cannot fully apply the brakes. In that case the Volt's forward collision warning may sound an audible and visual alert and the driver must apply the brake pedal. The Volt's Intelligent Brake Assist will automatically apply as much additional braking force as necessary (including up to and including activating the ABS) to minimize any impact.

In my experience the Volt's ACC can fall down on its job in certain situations:

A) The vehicle ahead of your Volt changes lanes or turns off the road. Just ahead there is a line one or more vehicles stopped in your lane. The ACC never detects these vehicles since they are not moving, the driver must apply the brake pedal to disengage ACC and stop the Volt or there will be a collision.

B) You are driving on a curved road, within the posted speed limit, using ACC. Around the bend there is a traffic signal and a line of stopped vehicles (yep, the ACC cannot detect these vehicles since they are fully stopped, not moving forward at all.) Apply the brake pedal to disengage ACC and stop the Volt or there will be a collision.

C) Similar to B except you crest a hill, the ACC radar is pointed at the sky as you come over the top of the hill. Just over the hill there is a traffic signal or a stop sign and a stopped vehicle. You guessed it, ACC never has a chance to lock on to this traffic (even if it has begun to move forward) and you need to apply the brake pedal to disengage the ACC and stop the Volt or there will be a collision.
 

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Yup, ACC, doesn't work for stop and go. The GEN2 Volt doesn't bring you to a dead stop, but I beleive that I remember reading that the BOLT will.
 

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Yup, ACC, doesn't work for stop and go. The GEN2 Volt doesn't bring you to a dead stop, but I beleive that I remember reading that the BOLT will.
I'm sorry but that is wrong on several points. 1) Under normal driving conditions the Gen 2 Volt, when equipped with ACC, will come to a complete stop (see my earlier response.) 2) The Bolt does not currently come with ACC, even as an option, so this is moot. 3) What the Bolt will do is allow the driver to drive in the L driving mode and the Bolt will slow to a full stop using regenerative braking. The Volt will not slow to a full stop when driving in L using regenerative braking. When driving a Volt in L you must apply the brake pedal once the vehicle speed has slowed to 2-4 mph to stop the Volt. (ACC is able to fully stop the Volt because ACC modulates the Volt's friction brakes.) The Volt has true blended braking so unless the Volt's traction control system has been activated due to a wheel slipping the Volt is always applying a combination of regenerative braking and friction braking.
 
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Yes, it works perfectly for me in stop and go city traffic and when the car in front of you stops, you will come to a gentle stop about a car length behind them

The way I use it is . . . . I set the cruise for about 5 mph over the city speed limit and then just follow traffic. If someone is speeding more than 5 over, they will walk away from you - Otherwise, you'll just follow them however fast they are going and stop when they stop. You do have to manually stop yourself at stop signs or red lights if there's nobody in front of you, but it sure makes it easy to keep up with traffic without worrying about a speeding ticket

Love it - Won't own another car without it. By the time I get ready to get something to replace the Volt, it will probably be required on all new cars, just as Back-up cameras will be next year

Don
 

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Why would that be the case? Isn't that exactly what it's for?
NO. It is for long distance highway driving, just like regular cruise control.
 

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Using ACC in a busy city setting would make me too nervous to actually rely on it all the time. Which at that point - why bother with it if I need to stay 100% on top of it just in case it gets confused and wants to plow into a car in front of it.


But then again, I'm not a huge fan in general of the level 1-3 autonomous systems due to their lack of robustness at handling all or even most environments.
 

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Why would that be the case? Isn't that exactly what it's for?
Hellsop is correct, so is jcanoe. It can absolutely be used in stop and go and that is where it shines. It can also be used on the freeway/highways and anywhere else. As we have stated before, it's a great driver's aid and very effective, although not in 100% of circumstances as has been covered before. Do a search for ACC on this site and you should get a number of useful hits.
 

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Using ACC in a busy city setting would make me too nervous to actually rely on it all the time. Which at that point - why bother with it if I need to stay 100% on top of it just in case it gets confused and wants to plow into a car in front of it.


But then again, I'm not a huge fan in general of the level 1-3 autonomous systems due to their lack of robustness at handling all or even most environments.
Once you experience it and test it in a variety of scenarios and understand how it works, it's quite effective. In mid to late afternoon sunny days where the sun is lower in the sky, when you go under say a tressel where the sunlight gets broken up (rare situation), you need to be extra vigilant. In 99.XXX% of other cases it works just fine. It can't see cars way ahead that are fully stopped, so don't use ACC cruising at speed into a traffic jam, take over there. There is a symbol (looks like a car) that shows up in the DIC showing you the car it sees in front of you. If the car ahead is too far out, you won't see that symbol. As you approach that car and catch up, it picks it up and goes from there. If you follow a car too closely, that symbol turns orange as a warning (I believe it's green when it sees the car ahead and you are at a safe distance).

These are a few things to note, experience is the best so try it out and be alert. You can quickly disengage ACC by tapping the regen paddle (I use that mostly), by hitting the brake or by pressing the button on the steering wheel to disengage ACC (I never do that, other options way easier).

The situation where I feel ACC is the safest is actually in slow stop and go type of traffic. It sees the car ahead, isn't going to lose it until traffic breaks up, and you are going slower speeds. If I have a tight tailgater, I'm probably disengaging ACC as it will brake at a similar pace to the lead car, and that might not work out too well with someone on your @ss.
 

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NO. It is for long distance highway driving, just like regular cruise control.
I've used cruise control for years in city driving. Anytime the speed limit is above 25 MPH and it's not a situation where you speed up to the speed limit followed by an immediate slow down for the next light or stop sign I'll turn it on. It's amazing how many speed traps I've avoided this way.
 
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Hellsop is correct, so is jcanoe. It can absolutely be used in stop and go and that is where it shines. It can also be used on the freeway/highways and anywhere else. As we have stated before, it's a great driver's aid and very effective, although not in 100% of circumstances as has been covered before. Do a search for ACC on this site and you should get a number of useful hits.
Keep in mind Hellsop responded to my statement:

"...ACC is not intended for stop and go traffic."

Emphasis on the word "intended". Just because something can be used under certain circumstances doesn't mean it was intended to be used in those circumstances. As I already stated if it was intended to be used in stop and go traffic then it should be possible to enable it in stop and go traffic (without having to reach a minimum speed of 15 MPH first). Likewise the owners manual speaks to limitations with ACC using stop and go traffic as a specific example.

However if the OP feels there's a problem with ACC in stop and go traffic I suggest he take it to the dealer and have them fix it. I suspect they'll refuse to do so stating ACC is working fine because it's not intended for stop and go traffic.
 

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The Chevy system is better in stop and go traffic because it's vision is relatively limited. Other systems that can "see" farther are better in fast freeway traffic. One thing with the Volt is that because it's using the regen brakes, if you need to quickly intervene the ACC/regen brakes disengage as you hit the brake pedal, and it takes some time before you get firm friction brake action.

Another thing I've found is that older systems would go out in the rain, but the Chevy (LIDAR based?) system does not have much problem with rain. I find this a real benefit since your vision is reduced in the rain. Having said that, in a real deluge, the Chevy system finally disengaged, and wouldn't reengage until it stopped raining and thoroughly dried out.
 

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Keep in mind Hellsop responded to my statement:

"...ACC is not intended for stop and go traffic."

Emphasis on the word "intended". Just because something can be used under certain circumstances doesn't mean it was intended to be used in those circumstances. As I already stated if it was intended to be used in stop and go traffic then it should be possible to enable it in stop and go traffic (without having to reach a minimum speed of 15 MPH first). Likewise the owners manual speaks to limitations with ACC using stop and go traffic as a specific example.

However if the OP feels there's a problem with ACC in stop and go traffic I suggest he take it to the dealer and have them fix it. I suspect they'll refuse to do so stating ACC is working fine because it's not intended for stop and go traffic.
How do you know, for a fact, that ACC is not intended for stop and go traffic?

Regarding ACC being speed limited at lower speeds. The exact wording in the 2017 Volt Owner's Manual, page 197 is "ACC will not set at a speed less than 25 km/h (15 MPH), although it can be resumed when driving at lower speeds."

The section of the 2017 Volt Owner's Manual that covers ACC provides a number of warnings including: not using ACC on winding or hilly roads, when visibility is low such as rain, fog, or snow conditions (darkness of night is not mentioned) or on slippery roads. I would think that if ACC was not intended for use in Stop and Go traffic then this would have been clearly included in the manual under warnings.
 
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How do you know, for a fact, that ACC is not intended for stop and go traffic?
I don't recall stating I knew for a fact. I said:

"...it was my understanding ACC is not intended for stop and go traffic."

Emphasis on the words "my understanding". Later I responded with something similar:

"That's not my understanding."

Again emphasis on the words "my understanding.

Regarding ACC being speed limited at lower speeds. The exact wording in the 2017 Volt Owner's Manual, page 197 is "ACC will not set at a speed less than 25 km/h (15 MPH), although it can be resumed when driving at lower speeds."
Since stop and go traffic is primarily associated with speeds less than 15 MPH wouldn't it be reasonable, assuming ACC were intended for use under such circumstances, it would be possible to engage (and not just resume) it at speeds below 15 MPH? Not being able to do so would seem to be an oversight in the design if it were intended for such conditions.

The section of the 2017 Volt Owner's Manual that covers ACC provides a number of warnings including: not using ACC on winding or hilly roads, when visibility is low such as rain, fog, or snow conditions (darkness of night is not mentioned) or on slippery roads. I would think that if ACC was not intended for use in Stop and Go traffic then this would have been clearly included in the manual under warnings.
Page 197 of the 2018 Volt Owner's Manual has the following warning under "Stationary or Very Slow-Moving Objects":

"ACC may not detect and react to stopped or slow-moving vehicles ahead of you. For example, the system may not brake for a vehicle it has never detected moving. This can occur in stop-and-go traffic or when a vehicle suddenly appears due to a vehicle ahead changing lanes."

Perhaps there's no such warning for the 2017 MY owner's manual. This suggests the system was not intended for stop and go traffic.

Again, if the OP feels ACC is not performing as intended under stop and go traffic conditions then I recommend he take his car in for service to get it repaired. There, I suspect, he'll be informed there is nothing wrong with the system as ACC was not intended for stop and go traffic.
 
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