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Discussion Starter #1 (Edited)
This video is in another thread but I can never find it, so I'll start a new thread making it easier to find when doing a search for Auto stop start.
The guy is long winded and managed to take 13 minutes to provide 3 minutes of info.
You can start at 6:50 without missing much.

 

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This video is in another thread but I can never find it, so I'll start a new thread making it easier to find when doing a search for Auto stop start.
The guy is long winded and managed to take 13 minutes to provide 3 minutes of info.
You can start at 6:50 without missing much.
So he's saying don't worry about the wear and tear on Starter Motors and Batteries, worry about the fact that you've got this system on your vehicle that you may not be able to turn OFF, that is not providing any real benefit to you (in terms of fuel savings), but may fail on you.
 

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The only thing that made sense in that whole video was at the very end. Use the time during the test drive to decide if the start-stop system is something you can tolerate.
 

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Discussion Starter #4
One thing I gained from the video is one of the pistons will stop at top dead center making for a effortless restart.
 

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here ya go...

Enhanced Starter Motor Operation in Engine Stop/Start Systems

Posted on November 30, 2017
The Engine Stop/Start system in GM vehicles automatically turns off the engine when the vehicle comes to a stop under certain driving conditions, and can quickly restart the engine in about 0.3 seconds when commanded to do so.

A Stop/Start system is available on
2014-2018 Malibu;

2015-2018 Impala;

2016-2018 Encore, Envision, CT6, Cruze;

2017 Verano;

2017-2018 LaCrosse, Regal, ATS, CTS, XT5, Trax, Acadia (VIN N); and 2018 Equinox and Terrain models.

In order to smoothly restart the engine as quickly as possible while managing the greater number of engine starts, the Stop/Start system uses an enhanced starter motor that operates differently from a conventional starter motor. (Fig. 6) It has a high performance electric motor and a stronger pinion engagement mechanism than a conventional starter. It also has independent control of the pinion and motor.




Independent Control

The enhanced starter motor continues using the typical pinion engagement mechanism with a starter solenoid that drives the pinion gear to engage or disengage the flywheel of the engine. When engaged, the starter motor can rotate the engine flywheel and, in turn, the crankshaft. However, there are two differences in the solenoid. It now has two parts.

On a conventional starter, the starter solenoid serves the dual purpose of providing the high-current switch that completes the battery positive current to the DC electric motor and the mechanical solenoid action to push the pinion gear into the flywheel of the engine. The Starter Relay (Fig. 7, A) is controlled by the ECM.

But on the enhanced starter of a Stop/Start system, these two functions are separated into two different functions inside the solenoid, with each function controlled individually by the ECM. There are two separate relays (Fig. 7, B) to control the two separate parts of the enhanced solenoid:

  • Starter Motor Relay
  • Starter Pinion Solenoid Actuator Relay
The two individually-controlled relays allow for smooth engagement of the pinion gear into the flywheel with minimum noise and wear.




Auto Stop Operation

When the vehicle is coming to a stop, just before the engine stops rotating (at approximately 50 RPM) during stop/start operation, the ECM energizes the Starter Pinion Solenoid Actuator Relay to easily push the pinion gear into the flywheel gear without gear clash. (Fig. 8) When the engine stops rotating during Stop/Start operation (Auto Stop mode), the starter pinion gear is fully engaged, ready for the starter motor to become energized to quickly start the engine again.




Slowing, but Not Stopping

A secondary need for the starter pinion to be driven into the flywheel gear before the engine stops rotating is to address quickly changing demands on the engine. For example, when a driver is slowing nearly to a stop — and the Stop/Start system is preparing for Auto Stop mode — but suddenly decides to release the brake and accelerate

In this situation, the engine has already stopped rotating, or nearly so. A conventional starter cannot restart the engine until the engine has completely stopped. However, with the enhanced starter, the starter pinion gear is fully engaged and ready to begin rotating the engine even before it fully stops turning. Otherwise, the engine would actually have to stop rotating before the pinion can engage smoothly to begin a restart.

To prevent a lag in engine operation, the ECM uses predictive speed matching of the flywheel gear speed and the pinion gear speed to engage the pinion gear into the flywheel gear without gear clash before the engine fully stops. By predicting how long it takes the starter motor to spin up using an algorithm, the pinion gear speed can be matched to the flywheel gear speed. The result is an almost instant restart that is possible at extremely low engine speeds.

– Thanks to Dan Jaszkowski and Jack Woodward
 

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So we're back to the Starter Motor (pinion) engaging the flywheel again. And OK - it's a "different" type of Starter Motor, but I don't know if this description makes me feel better, or worse, about this function.

Like I said earlier: the window motor is only going to open and close the window so many times before it quits. How many times is this Starter Motor going to pop that gear out before it quits? Or, how many times are these two gears going to mesh seamlessly before they don't (anymore)? And where will you be when either of these things happen?

Having a Starter quit on you in the morning before going to work, or at the end of the day before heading home from work, is one thing. Having it quit on you on a bridge in traffic is a whole different scenario.
 

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Discussion Starter #7
here ya go...

Enhanced Starter Motor Operation in Engine Stop/Start Systems

Posted on November 30, 2017
Thanks for the good info.
Even with checking the site every day or two I missed that post in November.
 

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So we're back to the Starter Motor (pinion) engaging the flywheel again. And OK - it's a "different" type of Starter Motor, but I don't know if this description makes me feel better, or worse, about this function.

Like I said earlier: the window motor is only going to open and close the window so many times before it quits. How many times is this Starter Motor going to pop that gear out before it quits? Or, how many times are these two gears going to mesh seamlessly before they don't (anymore)? And where will you be when either of these things happen?

Having a Starter quit on you in the morning before going to work, or at the end of the day before heading home from work, is one thing. Having it quit on you on a bridge in traffic is a whole different scenario.
ColtHero---I'm in agreement with your concerns; I was comfortable with the approach being engine stopped at TDC and then refired without starter engagement. This discussion puts me back in the uncomfortable category! I acknowledge that it is engineered to be as unobtrusive as possible, causes minimum inconvenience or driver awareness (until it doesn't work!), but I'm not convinced that the engineering has done anything to enhance the longevity of the components that are now being worked with significantly increased cycles of operation---and as we all know, it's the start/stop of a mechanical component that causes the greatest amount of wear, not the continuous operation.

Buried in all this discussion is another concern of mine that I had forgotten about over the past several days: Turbo bearing cooling and coking of the oil in the oil passages. Not certain that this has been addressed in any of the engineering for these turbo engines with start/stop feature. Coking used to be primary concern with turbos on passenger cars---specifically, the need to run for approximately 1 minute prior to shut-down. I'm seeing potential for problems developing at the 70-100,000 mile point--after the vehicle is out of warranty and GM has meet their CAFE requirements with small displacement engines for economy but still capable of power demands by consumer.
 

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No fears. .

BigB12359 exploring a hood switch mod to disable the Start/Stop. :grin:
 

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No fears. .

BigB12359 exploring a hood switch mod to disable the Start/Stop. :grin:


interested, if it sees the hoods open it will disable auto stop/start but it will also disable remote start curious to see how this plays out


Sent from my iPhone using Tapatalk
 

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interested, if it sees the hoods open it will disable auto stop/start but it will also disable remote start curious to see how this plays out
Yup. . I knew that and maybe one or two other side effects, plus it will turn a light on the DIC I think.

You could tie a relay in powered by "Ign-On" that would open the circuit only after you enter and start the car.
 

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Engineers’ arrogance. Should *never* design something in like this without a way for the driver to control it with some kind of auto/man setting.
 

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Engineers are most often told what they are to "design in". It has nothing to do with personal arrogance.

- - -smh
 

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Engineers are most often told what they are to "design in". It has nothing to do with personal arrogance.

- - -smh
Ok, well - I used "engineer" because that's what I'm familiar with. Who knows whose arrogance it was? That wasn't the point.

The point was: it's arrogant to put a new feature *like this one* into a vehicle without a way for the driver to control it.

And you *know* that question came up, but they did what they did.

It's arrogantly saying, "You're gonna have this feature, and you're gonna have to learn to live with it".
 

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It's arrogantly saying, "You're gonna have this feature, and you're gonna have to learn to live with it".
So the cars with cylinder deactivation have a way to disable it ?

And cars with Direct Injection don't have to use it ?

My tow examples, and the previous mentioned were put in place to achieve EPA mileage goals, and I suspect that if the owner can defeat it, then GM would not get full credit for it. Just my guess though. But, it would be nice if there were come hidden code that users could use - on the sly - to defeat it. There probably is, but only the arrogant engineers know it.
 

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So the cars with cylinder deactivation have a way to disable it ?

And cars with Direct Injection don't have to use it ?

My tow examples, and the previous mentioned were put in place to achieve EPA mileage goals, and I suspect that if the owner can defeat it, then GM would not get full credit for it. Just my guess though. But, it would be nice if there were come hidden code that users could use - on the sly - to defeat it. There probably is, but only the arrogant engineers know it.


direct injection is great for performance, never before could you run a turbo at 20psi on 87 octane and it be okay Direct injection isn’t a fair comparison tho because they couldn’t just put a switch to deactivate that! They COULD right now if they wanted offer a reflash for the bcm on the 2018 equinox and have the option to turn auto stop off show up in the DIC menu. It’s doubtful but maybe if enough complain it’ll happen 🤞🏻

our 2007 1500 ltz has multi displacement or cylinder on on demand or whatever it was called back then and you can turn it off. it RARELY enters v4 mode and when it does you don’t feel it kick in and out

chrysler allows you to turn off auto stop and rumors have it that the new buick envision will have a way to turn it off also. Somebody at gm must be listening to make it able to be turned off on those vehicles.


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So the cars with cylinder deactivation have a way to disable it ?

And cars with Direct Injection don't have to use it ?

My tow examples, and the previous mentioned were put in place to achieve EPA mileage goals, and I suspect that if the owner can defeat it, then GM would not get full credit for it. Just my guess though. But, it would be nice if there were come hidden code that users could use - on the sly - to defeat it. There probably is, but only the arrogant engineers know it.

I have AFM on my 2017 Colorado. No way to disable it that I know of. None on the two other forums I frequent have any threads about AFM disable.

But I suspect the questions are rhetorical. . .. . :smile_big:
 

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Generation 5 and 6 Camaro owners have been "tuning" out the AFM/deactivation feature since the 2010 reintroduction of the Camaro. Their biggest complaint was the way it sounded in 4 cylinder mode. Of course, the tune voided the warranty; most of them didn't care.
 
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