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Discussion Starter #1
I have a 2011 Equinix LTZ (I4). I drive the same route to work every day. In one spot, there is a hill where I can easily coast for a mile, not having to use the accelerator until I hit a specific crossroad. Lately, I have been noticing that it doesn't want to coast. It's almost like someone is putting the breaks on. The engine RPMs haven't changed. My speed hasn't changed. The weight of the vehicle hasn't changed.

I've noticed this coasting down a hill close to work as well. I'm usually doing 60mph, tranny is in 6th, and sometimes it will coast like crazy, and sometimes it feels like I'm pulling a trailer and I have to give it gas to keep it over 50mph.

Anyone else experience this? Any idea of what might be going on?
 

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I'm not sure if all equinoxs/terrains have an adjustable stop lamp switch, but the next time you are coasting on this hill put the top of your foot behind the brake pedal and pull toward you. If it seems to change how the vehicle coasts the switch may be sticking and slightly applying the brakes.
 

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The Equinox's engine/transmission are tuned to get the best fuel economy as possible. This means the engine tries to get to 6th as fast as possible when accelerating and downshift promptly when decelerating. The consequence of this (and of direct-injection) is that it is very hard to coast in this car...anytime you take your foot off the accelerator the car assumes you are going to be slowing down and will start hunting to downshift and give you the "braking" feeling you are getting. I experience it frequently. I find that throwing the transmission into manual before hitting a significant downgrade helps to alleviate this (and the dreaded upshift that makes you have to ride the brakes down the hill)
 

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Redhorseridge said:
I have a 2011 Equinix LTZ (I4). I drive the same route to work every day. In one spot, there is a hill where I can easily coast for a mile, not having to use the accelerator until I hit a specific crossroad. Lately, I have been noticing that it doesn't want to coast. It's almost like someone is putting the breaks on. The engine RPMs haven't changed. My speed hasn't changed. The weight of the vehicle hasn't changed.

I've noticed this coasting down a hill close to work as well. I'm usually doing 60mph, tranny is in 6th, and sometimes it will coast like crazy, and sometimes it feels like I'm pulling a trailer and I have to give it gas to keep it over 50mph.

Anyone else experience this? Any idea of what might be going on?
SIDI engines have very aggressive DFCO (de-acceleration fuel cut-off)...This is the "drag" you are filling, the ecm has actually cut-off fuel while you are coasting, thus causing this drag.
 

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I've noticed this too. Kind of annoying, I like to ride out the coast as much as I can. There is one very large hill in particular just outside of town. And I mean, large hill, it takes like a full 90 seconds to get to the bottom of it going 70 mph. Pretty steep. In my lil' ol' 2000 Mazda Protege (yes, super light and 4 cyl), I would take my foot off the gas at that hill and by the end of it I would have reached 85 mph. In the Nox...I'll still be at 70. Makes for a much less exciting ride. lol.
 

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Put your DIC on instantainous fuel milage and try it. You'll find that when you leave it in gear going down the hill the fuel is shut off, which causes the braking feeling and your milage is out of sight. When you put it in neutral to coast the engine is idling and using fuel and your milage is less than when you leave it in gear.
 

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gwhaley262 said:
I've actually noticed that if my 'Nox gains enough speed coasting it will "let go" possibly shifting up.
Thats the aggressive nature, the ECM will upshift and attempt keep the rpms up allowing the engine to essentially be cut-off, once it reaches a certain speed you will notice the engine come back to life with a "jump".
 

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ChevyMgr said:
I'm not sure if all equinoxs/terrains have an adjustable stop lamp switch, but the next time you are coasting on this hill put the top of your foot behind the brake pedal and pull toward you. If it seems to change how the vehicle coasts the switch may be sticking and slightly applying the brakes.
Would you mind expliaing what an adjustable stop lamp switch is? I'm asking because I've noticed on the Terrain and Equinox that the high-mount comes on before the regular lights. Is there a way to correct this?
 

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Phantm006 said:
Would you mind expliaing what an adjustable stop lamp switch is? I'm asking because I've noticed on the Terrain and Equinox that the high-mount comes on before the regular lights. Is there a way to correct this?
It will, because the taillights are incandescent bulbs with filaments that need to be heated up before you can see them, and the CHMSL is LED bulbs which will light up instantaneously - however, we are only talking an eye-blink or so difference in seeing the light - certainly not a second.
 

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Discussion Starter #11
I can coast in gear and in neutral and the instant mileage is the same: 99mpg.

I'll check the brake pedal.

I've thought about putting it into manual, but I hate that when I put it in manual in always shifts down a couple gears! My Malibu did not do this (if you put it in manual, it was in whatever gear you were in before). Does anyone know any way to override the downshift feature? I believe it's there for towing, which I will never do in this car...

What I don't understand is that sometimes it coasts like a BOH (bat out of, well you know), and sometimes it won't coast at all, on the same hill, at the same speed, in the same gear....
 

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Redhorseridge said:
I can coast in gear and in neutral and the instant mileage is the same: 99mpg.

I'll check the brake pedal.

I've thought about putting it into manual, but I hate that when I put it in manual in always shifts down a couple gears! My Malibu did not do this (if you put it in manual, it was in whatever gear you were in before). Does anyone know any way to override the downshift feature? I believe it's there for towing, which I will never do in this car...

What I don't understand is that sometimes it coasts like a BOH (bat out of, well you know), and sometimes it won't coast at all, on the same hill, at the same speed, in the same gear....
Coasting in neutral or in gear will produce similar results on the DIC

The way I watch DFCO is through a monitoring program on my laptop

If you put in neutral you have essentially removed DFCO from the equation, if the issue is still present while coasting in neutral that is not the issue...If the issue is not as present, then DFCO is your complaint, and present on all gDI engines I have driven (VW/Audi, Kia, and GM)
 

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Redhorseridge said:
...

What I don't understand is that sometimes it coasts like a BOH (bat out of, well you know), and sometimes it won't coast at all, on the same hill, at the same speed, in the same gear....
what is your foot position on the accelerator pedal for each scenario. remember this isn't a directly linked to the throttle system, you are giving input to the computer about your desired speed and state (steady, increase, decrease). there are also level sensors that the computer factors in (it knows the grade)... i've found that on hills, if I use the pedal to tell the computer what speed I want [i.e., traveling on a level road, when I get to the point where it goes downhill--don't lift my foot], and let it control what the engine/trans does, it will coast, if the situation is right...watch the tach and instant economy to see.
 

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grometsc said:
SIDI engines have very aggressive DFCO (de-acceleration fuel cut-off)...This is the "drag" you are filling, the ecm has actually cut-off fuel while you are coasting, thus causing this drag.
:thumb: Most likely what he is feeling, but I made my suggestion based on he felt it was acting differntly that his prior experiences.


Phantm006 said:
Would you mind expliaing what an adjustable stop lamp switch is? I'm asking because I've noticed on the Terrain and Equinox that the high-mount comes on before the regular lights. Is there a way to correct this?
As rit333 stated this is normal.

grometsc said:
If you put in neutral you have essentially removed DFCO from the equation,
Correct. Many people think they save gas coasting in neutral, but they don't.
 

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Not sure if my experience is relevant to OP's original post; however, since having 11195A performed on my '11 Nox I've noticed less drag with my foot OFF the accelerator.

Leaving my neighborhood, I descend two hills that total 4 miles in length. Prior to 11195A, to maintain the posted speed limit(s) I had to keep my foot [gently] on the gas, at all times.

Since the recall performed last month (ECM and Solenoids, albeit the old solenoids 47, 48), the 'Nox coasts much more freely on both hills with my foot off the accelerator entirely.

At least in my case, 11195 has resulted in several, noticeable improvements specific to engine idle, throttle responsiveness, shift points and coasting.
 

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Discussion Starter #16
CuHead said:
what is your foot position on the accelerator pedal for each scenario. remember this isn't a directly linked to the throttle system, you are giving input to the computer about your desired speed and state (steady, increase, decrease). there are also level sensors that the computer factors in (it knows the grade)... i've found that on hills, if I use the pedal to tell the computer what speed I want [i.e., traveling on a level road, when I get to the point where it goes downhill--don't lift my foot], and let it control what the engine/trans does, it will coast, if the situation is right...watch the tach and instant economy to see.
My foot is completely OFF the accelerator...once I crown the hill, I remove my foot.
 

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Is it possible that you sometimes have the A/C on when cresting the hill? If you recently quit using the A/C that will certainly change how a vehicle descends a hill.
 

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I live in Texas. My AC is literally NEVER turned off. Ever. lol.

And by the way, learned one time I was sitting in the waiting room for my car (I think it was my fourth trip in?)...if you ever have to replace the LED light up top, you have to replace the entire assembly, not just a piece or two. It's a couple hundred dollars... (If my warranty was over, I'd just drive without that light, you only HAVE to have the two regular tail lights)
 

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I've noticed with mine when I take my foot off the accelerator to slow down for a stop sign at exactly 28 MPH it feels like it drops about three gears, but there is a long hill I go down that even if I have it in cruise it will gain between 10 and 15 MPH.
 

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Don B said:
I've noticed with mine when I take my foot off the accelerator to slow down for a stop sign at exactly 28 MPH it feels like it drops about three gears, but there is a long hill I go down that even if I have it in cruise it will gain between 10 and 15 MPH.
Could be the engine turning back on, it depends on the situations....If I'm watching what the engine does, I can tell when the engine goes back to a lower gear and turns on, the RPMS will typically drop to around 1K....I thought it turned the engine back on @ 24mph, and DFCO does not engage until you go above a certain speed as well (I think its 40+mph, I just have not checked it in along time)

From a HFV6 article when I was researching the Aussie 3.0 (being it had torque @ 2900rpms vs ours @ 4xxx)

Deceleration fuel cut
• Operating range of this feature has been optimised for minimal fuel consumption at MY10.
• When decelerating or coasting downhill, fuel supply to the engine is seamlessly cut where fuel is sequentially cut off per cylinder.
• At a certain speed and load input, fuel is seamlessly reinstated when required


Its something we are going to have to get used to, the first time I felt it I thought I had something wrong with my car, as it "bucked" (not my nox but on an VW GTI). Its very normal, and the newest and soon to be greatest technology will be NO IDLE! Its what many manufactures are working on to reduce emissions as well as fuel consumption....Our engines already idle @ 550rpms (the 3.0L does, the 2.4 is slightly higher). , I believe they are calling that start-stop technology and expect to see it in a few years on all cars! The general public is going to have to get used to new ideas, and changes....The DFCO is agressive w/ gDI, and it will get even more agressive as time goes on.

All these features are what is needed in ordered to meet the required mpg and emissions.
 
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