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Discussion Starter · #1 ·
I have a 2011 terrain i4 fwd and I have noticed that when I pull in my apt complex after stopping at a stop sign-I accelerate briefly then "coast" to my parking spot the transmission seems to SLAM into a lower gear. Is this normal?
Also if I reset the avg mpg after filling up the number starts at 22 and drops as low as 13 before I begin to drive. Is this normal? My mpg overall for mostly short drives is 19/20. And highway driving @70 yields 25.5 mpg. Seems very low, right? 10,100 miles and had one oil change. Thoughts?
 

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MakeItTerRain said:
I have a 2011 terrain i4 fwd and I have noticed that when I pull in my apt complex after stopping at a stop sign-I accelerate briefly then "coast" to my parking spot the transmission seems to SLAM into a lower gear. Is this normal?
Also if I reset the avg mpg after filling up the number starts at 22 and drops as low as 13 before I begin to drive. Is this normal? My mpg overall for mostly short drives is 19/20. And highway driving @70 yields 25.5 mpg. Seems very low, right? 10,100 miles and had one oil change. Thoughts?
I had a 2011 that was Lemon Lawed and although I to had that hard shift which at that time I thought was "normal" it never got adressed ahead of all the other issues I had.I can say the Terrain I am in now,also a 2011 has not had that hard shift with 3,000 miles on it so if it starts it will not be "normal" to me.When I reset my average MPG it usually goes to like 22.5 and then proceeds to it's next point.Maybe you should have it checked out and see if any codes have been thrown.
 

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I would also recommend bringing this to the attention of your local dealer during your next visit if you are concerned. Please feel free to keep me posted. Thank you.

Tricia, GM Customer Service.
 

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MakeItTerRain said:
I have a 2011 terrain i4 fwd and I have noticed that when I pull in my apt complex after stopping at a stop sign-I accelerate briefly then "coast" to my parking spot the transmission seems to SLAM into a lower gear. Is this normal?
Also if I reset the avg mpg after filling up the number starts at 22 and drops as low as 13 before I begin to drive. Is this normal? My mpg overall for mostly short drives is 19/20. And highway driving @70 yields 25.5 mpg. Seems very low, right? 10,100 miles and had one oil change. Thoughts?
My 2011 I4 does it at exactly 28 MPH when I let it coast. There was a thread about this some time ago and I don't remember what the answer was but the person that posted the answer had an explanation that made it sound like it was normal and I don't remember anyone disputing him.
 

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I have a 2011 Terrain I bought about a year ago at Aitken GMC/Chevy/Buick in Simcoe Ont, Canada. I too have the HARD shift issue when letting off the throttle at 20-30 km/hr it feels as if the transmission wants to shift into 1st gear does and then shifts into the proper gear all at the same time. and the gas mileage is lower than advertised right now i get about 700-800 kms to a full 60 liter tank. I have about 40,000 kms and have had 2 oil changes based on the oil life monitor. first at 50% second at 30% and I am booking my next one tomorrow. I do mostly highway driving and some in town driving. I stopped driving in ECO mode and saw the hard shifts become less frequent and gas mileage improve (a small almost unmeasurable amount but still an improvement.) I do love my terrain and these problems are first generation issues that should be addressed by GMC. I have been a GM fan all my life and this issue is beginning to concern me and the stuff I am reading on the forums is concerning me that they think this is normal operating and isn't a problem but soo many people have this "issue" and I feel this needs to be addressed ASAP. so in short YES I HAVE THIS ISSUE ALSO.
 

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Discussion Starter · #7 ·
I too recently turned off eco mode and noticed the hard shift stopped! Tonight I turned it back on and noticed it again. I think I may lear it off unless someone can tell me I will have significant better gas milage with it on. Thanks for input!
 

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MakeItTerRain said:
I too recently turned off eco mode and noticed the hard shift stopped! Tonight I turned it back on and noticed it again. I think I may lear it off unless someone can tell me I will have significant better gas milage with it on. Thanks for input!
Exactly like it supposed to. In ECO mode it shuts off the gas to the engine while decelerating like a semi jake brake especially useful going down hills. It also locks up the torque convertor sooner and keeps it locked longer (that causes the "dieseling" when accelerating in higher gears at low rpms) all perfectly normal operation in ECO.
 

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My I-4 2011 Terrain also had the hard shifting..in and out of ECO mode..

Then it started having a slipping trans when excelerating and shifting through the gears...

I was getting 19-21 MPG avg..IF on a long trip on the freeway, in ECO model I could get 23-24 MPG.

My 2012 V6 Terrain, at 500 miles...Im getting 18-19 MPG..! ;D
 

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Mochaman ECO mode changes your throttle response and your shift points I do not believe that it shuts the fuel off to your engine and lock the torque converter. It don't operate like a jake brake (A jake brake opens the cylinder for "engine braking" to stop ignition and compression to help a semi slow faster.) ECO mode is garbage and I do not notice a change in my fuel mileage (with it on I still get the same as if it off) I have almost 50,000Kms on my Terrain and I get about 850 Kms with premium fuel only in my car. I only drive it in "Standard mode" and I have no problems since I have turned it off.
 

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Diggydan said:
Mochaman ECO mode changes your throttle response and your shift points I do not believe that it shuts the fuel off to your engine and lock the torque converter. It don't operate like a jake brake (A jake brake opens the cylinder for "engine braking" to stop ignition and compression to help a semi slow faster.) ECO mode is garbage and I do not notice a change in my fuel mileage (with it on I still get the same as if it off) I have almost 50,000Kms on my Terrain and I get about 850 Kms with premium fuel only in my car. I only drive it in "Standard mode" and I have no problems since I have turned it off.
:nono: Wrong
AUTOMATIC GRADE BRAKING
To prevent unwanted acceleration and reduce the need for the driver to brake during a hill descent, the 6-speed automatic with overdrive features Automatic Grade Braking. This “smart” feature monitors braking, acceleration, throttle position and even whether a trailer is connected to the vehicle. Then it commands the transmission to remain in a lower gear if the vehicle is decelerating or coasting on a downgrade to help you hold your desired speed and minimize the need for additional braking the Ecotec four features an "ECO" mode in which the driver can lower torque lockup speed to 1125 rpm with the touch of a button. However, even when running the Terrain on unleaded fuel, it has the capacity (when activated) to operate in Eco Mode which assists in lessening fuel usage while driving. A few ways Eco mode is able to achieve better mpg is by automatically upshifting earlier than normal, causing the gas pedal to be less sensitive and by using the main computer (brain) to automatically shut off fuel supply during deceleration.

Everything I said is true check your sources. :thumb:
 
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