ECO with Auto Tranny driving in Manual Mode

[Bergy9]

I have a question, I have a 2012 ECO with a AT. This morning while going to work I decided to drive it with the tranny in the manual mode. I ended up behind a slower moving vehicle so I decided to pass. At this point I am in M5, I stomp on it to go around the vehicle and the tranny down shift's (rpm's Jump up) and as I am completing the pass it up shifts I pull back into my lane, the tranny shifts back to M5 or seems to be back into M5 (rmp & speed increased) I then shift into M6, and then switch back to auto. I am wondering if this is normal, and if it is then what is the point of driving in manual mode? I also noticed this while going up a hill as well, at the approach to the hill I was in M6, 3/4 the way up the car down shifted, at which point I slapped it over to auto.

I guess I was thinking in the lower gears it would be no different than driving my truck in 3 verse's D which will not shift up or down until I shift it myself.

[spacedout]

There was another user on here that says his automatic with still downshift in manual mode with more than 1/4-1/2 pedal throttle input, he also has an eco.
My 2012 1LT automatic does not downshift at all, at full throttle it will still hold whatever gear I have selected. Only automatic shifting it does in manual mode is downshift if my speed falls to low for the gear I have selected, at 40mph it drops from 6th to 5th, at 28mph it drops from 5th to 4th.

Even if your car(or all eco autos as it seems) downshifts on throttle position even in manual mode there is still a use. if you are driving on a downhill grade & need some compression braking, driving on a curvy road & need more power, or hovering around shift point speeds.

The shift point speeds one being the biggest, an example would be going 35-45mph to keep the trans from hunting for gears(shifting continually unnecessarily between 5th & 6th), you could use M5 until you could go a more constant speed above 42mph(where the trans shifts to 6th).

[spacedout]

There has been a few times where I went to pass a slow moving car & forgot I was in manual mode, flooring the gas in 5th & worse yet 6th there is nothing there. This could be dangerous so in a way I would prefer mine work like yours.

The way yours works its more like telling the trans don't up shift past this gear, as in your example 5th. If one needs more power & floors it the gas it will still give you the power you are demanding. The way yours works is exactly how most if not all other automatic cars/trucks work, including the 2012 impala I recently drove.

[hawkeye]

I also have an Eco automatic (2011), and mine does not downshift if manual mode. I've gone to pass and had no power, looked down and saw that I was in 6th, then manually popped it to 5th to pass.

[spacedout]

There may also have been a change mid model year to how the trans works, my 2012 1LT RS was built in January. Hopefully more 2012-2013 automatic users chime in.

[Bergy9]

Thanks for the replies, it was suggested to me to drive in M6 to help with the MPG's, so that is how I discovered the tranny will down shift while going up a hill, and then this morning I was expected the tranny to hold in M5. So far, some trannies hold, some down shift. Maybe because of the no / low power when passing this became a safety issue, and maybe GM changed the tranny to react to throtle position regardless of manual or auto operation.

[spacedout]

Maybe because of the no / low power when passing this became a safety issue, and maybe GM changed the tranny to react to throttle position regardless of manual or auto operation.

I think you hit the nail on the head there. That's why I hope more 2012-2013 automatics report in, eco or others.

[Sunline Fan]

2/23/12 build here, and it'll hold the gear, which is why I love it so much. Only reason why it shifts is if I slow down enough to cause it to downshift.

[Bergy9]

I just did a google search and found nothing, hoping more will reply.

[spacedout]

I did find the post from earlier this year where I discussed this with another user, their 2012 eco automatic downshifts with the throttle in manual mode. I sent him a PM tonight, hopefully he will also chime in & give a build date. Here is a link to that post: Driving in "M" mode with the 1.4L Turbo automatic ??

From everything I have read tonight after your post all 2011 automatics do not downshift with throttle input eco or otherwise. We really need more 2012-2013 cars to report. If people know there build date that would be helpful, mine was listed on my window sticker though you can tell by the vin number too.