A8 at the dealers

Glava2876 · October 5, 2015

As I posted before, my 2015 Denali 6.2 A8 (1,800 miles) started having a very loud bang as it went from 2nd to first, it didn't matter if I was braking hard or soft.

I brought it to my dealer Friday and they called near the end of the day to say that they had tried all of the GM bulletins etc. and it still does it -they had never had this problem with the A8 and they are a pretty big dealer in CNY.

They said they would be in contact with GM support today.

They gave me a new 2015 5.3 A6 to drive over the weekend -black double cab SLE with the extras package and Z/71 -real nice truck ...and man I want my A8 to shift from 2nd to 1st like this A6 does!

I know that it was luck of the draw, that some of us will have problems and as I've said before, my truck is awesome.

I know that one way or another GM will get to the bottom of this problem.

I will pass on what they end up doing to get it straightened out.

Glava2876 · October 5, 2015

As I posted before, my 2015 Denali 6.2 A8 (1,800 miles) started having a very loud bang as it went from 2nd to first, it didn't matter if I was braking hard or soft.

I brought it to my dealer Friday and they called near the end of the day to say that they had tried all of the GM bulletins etc. and it still does it -they had never had this problem with the A8 and they are a pretty big dealer in CNY.

They said they would be in contact with GM support today.

They gave me a new 2015 5.3 A6 to drive over the weekend -black double cab SLE with the extras package and Z/71 -real nice truck ...and man I want my A8 to shift from 2nd to 1st like this A6 does!

I know that it was luck of the draw, that some of us will have problems and as I've said before, my truck is awesome.

I know that one way or another GM will get to the bottom of this problem.

I will pass on what they end up doing to get it straightened out.

The dealer just called saying that they did a series of things that GM technical wanted them to do, but the dealer tech is not completely satisfied and wants to keep it another day so they can work with it a little more -I'd rather have it back correct Vs fast and it's nice to know the dealer wants to do more.

sahls01gmc · October 5, 2015

Hopefully they can find the problem. Have they been able to replicate the issue?

TxTruckMan · October 5, 2015

Good luck. Please keep us informed.

Glava2876 · October 5, 2015

Hopefully they can find the problem. Have they been able to replicate the issue?

Yes, it does it all the time and they confirmed that it did it when they stopped.

sahls01gmc · October 5, 2015

Well, at least they have a first hand account on what is going on.

thewhitestallion · October 6, 2015

Sounds like you have a reputable dealer and I am sure it will get handled one way or the other. Sucks to hear that you are having issues though! GL

Glava2876 · October 6, 2015

Well, the service department called and it was on the lift all day today, the tech is trying everything to get this corrected -so they are keeping it another day.

Glava2876 · October 7, 2015

The dealer called and they have gone though all the software/ relearn processes and just finished up.

Said that the tech wants to just want to keep it overnight, so that they can try it with everything cool in the am. Hopefully it is fixed and the paperwork has the details that I can pass on for anyone else that has this problem.

smrr1 · October 7, 2015

Sounds like an awesome service dept. Congrats on that. Hope the truck is fixed.

Glava2876 · October 9, 2015

As I posted before, my 2015 Denali 6.2 A8 (1,800 miles) started having a very loud bang as it went from 2nd to first, it didn't matter if I was braking hard or soft.

I brought it to my dealer Friday and they called near the end of the day to say that they had tried all of the GM bulletins etc. and it still does it -they had never had this problem with the A8 and they are a pretty big dealer in CNY.

They said they would be in contact with GM support today.

They gave me a new 2015 5.3 A6 to drive over the weekend -black double cab SLE with the extras package and Z/71 -real nice truck ...and man I want my A8 to shift from 2nd to 1st like this A6 does!

I know that it was luck of the draw, that some of us will have problems and as I've said before, my truck is awesome.

I know that one way or another GM will get to the bottom of this problem.

I will pass on what they end up doing to get it straightened out.

FIXED!!

The tech at the dealer (Bill Rapp GMC Casey Jones)was not sending the Denali back until he was satisfied with it -man am I satisfied!

This transmission downshifts smooth as silk through all the gears ... and still goes though the gears like stink when I mash the pedal!

He did the following:

1) UPDATED TCM SOFTWARE, PERFORMED FAST LEARN ADAPTS AND ABBREVIATED COAST ADAPTIVE DOWNSHIFT ROUTINE AND VERIFIED REPAIR.

2) RECALL 9101695 PROGRAMMED TRANSFER CASE SHIFT CONTROL MODULE. Prevents 4wd always engages when cold.

3) RECALL 9101552 REPLACED TRANS INTERNAL HARNESS WITH INTEGRAL TFT SENSOR. Prevents harsh shift when starting in cold temperatures.

Thanks to my dealer, I am extremely pleased with my Denali!