[David Decker]

I recently purchased a CXL 2008 Enclave loaded with options and drove it 2000 miles on a trip. It drove nicely with one exception, transmission shifting. It hesitates badly when you manually press the accelerator while for example passing another vehicle. It seems to downshift nearly alright however when in Cruise Control except it always downshifts two gears and then comes back up one gear soon afterwards. This is annoying and probably over-stresses the engine. You would think that GM would get their new transmission downshifting properly and maybe a tad earlier when in Cruise Control but then have it downshift only one gear range so that excessive engine revving doesn't occur. I may see what the dealer has to say about this but I suspect they will defend GM and say that everything is operating as it was designed to even though there is bad manual downshifting hesitation and when in Cruise that downshifting 2 gears and then coming back 1 is as designed. I wonder!

 

[jonv112]

Welcome to the forum! :welcome:

There is a rumor circulating that GM is going to have another transmission update in the near future, and everyone on the forums will be notified when this happens by our insiders.

 

[zman]

Welcome to the forum! :welcome:

There is a rumor circulating that GM is going to have another transmission update in the near future, and everyone on the forums will be notified when this happens by our insiders.

Yep. August sometime is the latest word from insiders.

 

[BuicksRbetter]

The Enclave that I test drove didn't know what the **** to do when I floored it...very annoying. :sosad: I was really surprised since GM transmissions are always very responsive just when you want them to be. I ordered mine about two weeks ago, and I'm really hoping they have this corrected by the time I take delivery.

 

[jonv112]

LOL it is a ford transmission. NUF SAID!!!!! LOL GM and ford did a joint venture to build this 6 speed. they are supposed to be reprogramming them. My bet is there will be a recall so you guys can get the PCM reflashed and it will shift differently.

I knew it was a Ford thing all along! Nothing good comes out of that company nowadays.

 

[OldDan]

I just purchased mine today, from a dealership 6+ hours from home (only place I could find configuration I wanted). The ONLY problem I found in the long drive home was this downshift problem. It's definitely noticeable, so I hope they come up with a fix soon!

 

[ItsaBuick?]

Yes, I finally have taken a long summer trip in the Enclave and the cruise control and down shifting is horrible. :angryfire:
Any small grade and it's double downshifting and in cruise it only comes back one gear ( 1st overdrive of 2 ???). If your not paying attention you'll loose MPG as it runs 200-300 RPM higher. It is stupid that I have to turn off cuise and then turn it back on just to get in the right gear.

They really should have worked this out before launch. POOR JOB GM. I don't think Lexus would have put this into production this way. Maybe it's becuase this tranny was a joint venture with Ford. Too many cooks in the kitchen.

Anyone in hilly terrain must really be pissed. I live in IL which is relatively flat and I'm not happy.

 

[gavine]

I noticed when in manual-shift mode and in 6th gear, if you downshift to 5th gear, it goes down to 4th instead. I just figured it did this on purpose because going from 6th to 5th doesn't really buy you much but going to 4th really gets the VVTI going and utilizes the high-RPM horsepower.

Even if it was designed that way, I don't like it. I'd rather it let me go to 5th and I'll decide if I want to go to 4th (in manual mode).

 

[netmag]

Yes, so far I like everything about the vehicle but the shifting. I have not played with the +/- buttons yet.
The shifting is the worst on hills and when trying to get on highway ramps. The indecision and slowness of the shifting response is definitely irritating. However, I knew this going in.

From what I hear thought, there is an update to the shifting algorithms coming out this month. It's supposed to greatly improve the shifting (not sure if it'll change anything with the +/- buttons though, but I'm mostly concerned with improving the normal every day shifting). I will be at the dealers as soon as the code update is released to them. Supposedly, lambdas built in early August will come with the new shifting updates already applied.

Check out some of lzwhb2's latest posts where he comments on the new transmission calibration:

http://www.acadiaforum.net/forum/index.php?action=profile;u=207;sa=showPosts

 

[coopermine]

I agree with you all. My biggest gripe is that it is very hesistant in climbing highway ramps, or up hills. I hardly use cruise control, so haven't noticed the double down shift yet. I will be glad if the downshifts can be a little more responsive.

By the way today is August any news on the software upgrade yet?

 

[netmag]

lzwhb2 is also a member here but he posts most often on the Acadia forum so I try to keep an eye on his posts there.
He said yesterday that lambdas built starting today (Aug. 1st) will have the new transmission shifting algorithm already applied. Hopefully, that means they'll also give it to dealers as a Service Bulletin really soon.

 

[Canuck]

Please supply a link to the Aug 1 statement. Thanks

 

[netmag]

Follow the link in my earlier post (4 posts up from here). That shows all the latest posts made by lzwhb2 on the Acadia forum. He's one of the engineers who has specifically worked on the new calibration.
He mentions Aug 1st in his second to last post (2nd one from the top; dated Yesterday)

 

[Canuck]

Thanks

I must have been asleep. I read the item on the Acadia forum but must have read it as Aug 15 not 1 :banghead:

 

[raftdoc]

Recently did my first prolonged driving in our Enclave(it's my wife's car) on a trip in mountainous terrain on mostly 2 lane roads requiring plenty of passing, etc. I found that with some practice and getting a feel for how the manual shifting works, I was able to get the transmission to do pretty much just what I wanted it to do. While this was great for performance, I'm sure the mpg took a hit. I agree that the automatic shifting algorithm is very frustrating in this sort of driving.

 

[sosoeddie]

Raftdoc, like you, when I used the manual +/- shifting for the first time on a recent mountain road outing, it worked well. However, when I last tried to use it, I was going probably 45 when I shifted down to "L" and the car jumped (NOT GOOD) as the transmission went in 2nd gear. I had assumed that it would go into 4th or 5th gear and then I could shift down to the gear I wanted. QUESTION: how do you know which gear it will shift into? and how do you avoid shifting to too low a gear?

 

[sunshadw]

QUESTION: how do you know which gear it will shift into? and how do you avoid shifting to too low a gear?

Mine seems to reflect whatever gear the vehicle is currently in while in the "D" range. It could drop one gear under though.
Wayne