A8 hard 2nd to 1st down shift FIXED at dealer

Glava2876 · October 9, 2015

I just wanted to be sure this is on the site incase anyone has an A8 with a real hard 2-1 down shift bang.

My dealer had it for almost a week, but it is now 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!

Stevens03 · October 9, 2015

Congrats, I still believe there are some dealerships that actually care about customer service.

TxTruckMan · October 9, 2015

What about the sluggish first 1-2 upshift when cold? Did you have that?

Glava2876 · October 10, 2015

No, my problem was only that when I was slowing down to a stop, the shift from 2nd to first banged like you hit the bed with a shovel. Now you don't even feel anything as you come to a stop.

The up shifts were and are great.

Badass69 · October 11, 2015

Mine does the sluggish 1st to 2nd shift when cold on it's first shift and then clunks and clanks until it warms itself up a bit. By the sounds of things 9101552 would fix that but then I have to fight with numpty dealer service departments that won't fix anything because every single problem under the sun is "normal"...... and a possibly competent one is at least 150 miles from my home and I don't feel like trailering the truck or finding a ride from a friend...... no one does "loaners" here. I wonder if I can buy the harness and swap it myself lol. Transmission valve bodies don't scare me.

But if that number is for a recall...... shouldn't any of us affected get a notice in the mail to repair it? It's not like it's a TSB.........

http://oemdtc.com/19451/harsh-shift-when-starting-in-low-temperatures-2015-cadillac-chevrolet-gmc-vehicles

According to that my truck should be fixed already as the dealer should have performed the work while the truck was still sitting on the lot.......

redwngr · October 12, 2015

It does say the update for the harness/thermistor is serial number dependent.

Badass69 · October 13, 2015

I will just buy the harness and swap it at home. Problem eliminated lol.

Sent from my potato

Glava2876 · October 13, 2015

Sorry, I had some numbers mixed up;

9101695 is Recall 15304

9101552 is Recall 15396

Badass69 · October 13, 2015

Booked mine in today for Saturday. Open campaign on mine for the transfer case control module but that's it. I told them about the cold rough shifting and will leave it there Friday night so there is a hope they will find the rough shifts when its cold. And they can change my oil....

Badass69 · October 17, 2015

I have to go pick up the truck to see if there is a change but I had both the tccm reflashed and the harness with the thermistor changed in my truck today. Hopefully all is well!

Sent from my potato

Badass69 · October 18, 2015

I just wanted to be sure this is on the site incase anyone has an A8 with a real hard 2-1 down shift bang.

My dealer had it for almost a week, but it is now 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!

Had the exact same thing written on my work order. The truck seems to shift normal now when its cold and that's all I was worried about! Well and having 4wd work in the winter is nice..... lol.