Serge, while driving...

[felixgun]

Yea Jacob the 07 Avy/Tahoe/Burb/Yukon came with AFM but it wasn't until 08 or 09 for it to be released on the 6.2L Yukon Denali, then not until 2010 for Esky's to get it. Since my Esky is an 07 I don't have it which is probably why i'm getting 11.1 mpg.

 

[Diabology]

I thought there would be a pic of Soulsea driving (literally) in here based on the title of the thread...

x4

 

[KMeloney]

Same issue here, but most noticeable @ 30 mph. I have referred to it as "bucking" in other threads. I think it's a trans thing, and not a fuel management issue. But, then again, I don't know if the two are separate.

 

[Goodinblack]

X5.

What ^^^^^ KMeloney said. I experience too.... Have you found a fix for it or is it just "normal" ?

 

[Denali239]

Yes bucking is a great way to describe it. Thank you for the advice. I will be checking the trans fluid later on today. I contacted the dealer and they confirmed the 6.2 in 07 does not have displacement on demand so I can rule that out. I have an extended warrany on the truck, however I dread taking it to the dealer for something that isnt consistant because 99.9% of the time they say everything is normal.

 

[KMeloney]

I haven't gotten mine to the dealer yet. I, too, suspect they'll say it's normal -- and that's why I'm trying to get as much info about it at possible first.

 

[mike1944]

Yea Jacob the 07 Avy/Tahoe/Burb/Yukon came with AFM but it wasn't until 08 or 09 for it to be released on the 6.2L Yukon Denali, then not until 2010 for Esky's to get it. Since my Esky is an 07 I don't have it which is probably why i'm getting 11.1 mpg.

You aren't missing much. I played with my 2010 Denali quite a bit on one long trip.

It usually only kicked into 4 mode when it was a constant speed, below 45 mph, and it was flat or downhill. Higher speed or any grade, no matter how slight, would pop it back into 8.

There was no noticeable kick/noise/surge/etc. when it did change.

 

[GM Customer Service]

Yes bucking is a great way to describe it. Thank you for the advice. I will be checking the trans fluid later on today. I contacted the dealer and they confirmed the 6.2 in 07 does not have displacement on demand so I can rule that out. I have an extended warrany on the truck, however I dread taking it to the dealer for something that isnt consistant because 99.9% of the time they say everything is normal.

Please keep us posted of the results of your dealer visit.

Please feel free to contact me if you have additional questions.

Louis
GM Customer Service