eboggs_jkvl

Len, honestly, yer confusing the hell out of me!

If you have the A6 or A8 in "Drive" it will shift back and forth when it feels the urge from V8 to V4. If you have the car set to "Manual", it stays in V8.

I think the poster was referring to the V4 mode as the ECO mode, not necessarily having the Mode switch sitting in "ECO". Now if he was referring to the M7, then ECO is the only way to get to the V4 mode.


Right?

Elmer

Len44

Yep, I think we're in violent agreement.

I guess I was confused by the comment that "Automatics are in Eco all the time", which, of course, is not true.

Mobil 1

When did they start using the updated A8 trans? Production date....

bbcb

great question ....

Boucherman

From the 2015 Owners Manual page 9-42


"ACTIVE FUEL MANAGEMENT (engine cylinder shouts off) 4-Cylinder Mode

Normal with automatic transmission: The engine uses 8-cylinder mode when accelerating, but changes to 4-cylinder mode when coasting.

With manual transmission: Active Fuel Management only active in ECO mode.

Off in Manual mode with automatic transmission unless in ECO mode."

So where did I go wrong???

\Boost Monkey/

Black&White, our resident transmission issues expert, says it was sometime in October or November of 2015 if i remember it right.

So even early 2016's have the unrevised transmission.

joemessman

It was October.

red 1

Don't give black and white a hard time, I went through the A8 battle with GM and finally won and got the trans replaced with the new version and it works great.

Black&White

Im told about mid October 2015

Always Red Dave

CRAZY SITUATION GOOD LUCK!

Len44

I think we may just be dealing with semantics, in that we both know what we meant in our posts.

In this instance, when I saw your comment, I'm recalling that when I am driving down the road in Auto, it changes between V4 (ECO) and V8. Therefore (I am thinking, looking at your comment), that the car in most definitely not in ECO mode at all times, since the engine moves from V4 to V8, and V8 to V4, as designed.

My response concerned the comment, "Automatics are in Eco all the time"

I do not disagree with the portion of the manual you provided.

I think we both understand how this actually works. I must have somehow mis-interpreted your comment. Perhaps you can help me with where I went wrong.

Mobil 1

My production date is 10/15

\Boost Monkey/

Lol, actually, he's the first to bring the information (that I know of) to this forum about the revised transmission, which to me is valuable knowledge. So all joking aside, I consider that a valuable contribution, as is the information about the TC being the root cause.

Knowing my A8 could grenade one day when I get in the vicinity of 10k miles (which seems to be the sweet spot for some reason) I want to be ready and I need this info to do so.

So you said it was the TC as the root cause, do you have any idea what exactly or close to the changes were on the revised version? A revised TC only?

bbcb

just great .... mine was built August 2015 ......

OL2yellr

~ 7k miles on my 15 Z51, no problems.....

red 1

My A8 went south at 600 miles, the new trans was finally installed in Dec of 2015 with the new part number along with a new tcm that was replaced the week before the trans.

dino333

I have 6400 miles on a 2015 A8 base. So far so good. Built on 3/25 Museum Delivery 4/14/15.

Maxie2U

My 2016 was built on 10/15, wonder how I find out if I actually have the revised tranny or the previous (trouble plagued) revision?

Black&White

I do not know what exactly was changed. However it was enough for them to have to give the A8 a whole new part number. The whole mess has to do with fluid draining out of the T/C too quickly causing loss or intermittent forward motion like the pulsing or jerking or in some cases no forward/reverse engagement at all as others here report. As I understand it the A8 T/C is kind of a one piece assembly and if one goes it takes the other with it. I was told by GM that they had a fix in the works a series of check valves that could be installed in the bad ones but to date no one knows of a part or TSB number for it yet.

HANNY

bummer, haven't had or heard of a lot of issues with the A8 but there will always be a few,,,,,, good luck with it