donniegilbert

I recently purchased a 2016 Yukon XL Denali with 90K miles. Even on the test drive, I thought that the 1-2 shift was a bit harsh. Well, even after being at the GMC dealer several times it STILL shifts harsh... or sometimes it decides it doesn't like second gear at all and skips that gear, basically going from 1st to neutral to 3rd... with a large spike in RPM's sometimes bumping off of the Rev limiter dependsing on where my foot is on the pedal. Here's what has been done. P0711 code was found. A new Trans Temp sensor was installed. Fluid Flushed with the newer Mobil 1 fluid as per a TSB for Shutter condition. A QUICK LEARN was done for the TCM. Result - No difference in shifting. 1-2 bangs in (especially on cold start up). At WIDE OPEN THROTTLE, 1st is good, then when shifting out of 1st, it goes into neutral, engines hits the REV limiter, 2nd SLAMS into gear, rear wheels chirp, then shifts into 3rd. The rest of the gears are fine. Second trip to the dealer. An EXTENDED LEARN with Individual Clutch Pack reprogramming was done on the TCM. Basically the same result as above.  BUT........... Sometimes the dumb thing shifts like it is supposed to, so to me, that indicates that the internals of the transmission as working, but only WHEN THE COMPUTER DOES IT'S JOB RIGHT !!!! I have looked through previous posts, printed them for the tech at the dealer, he read them, and basically he said that there is nothing he is capable of doing. On a different note, I spoke to a 2016 Yukon owner last night, and he said that he got a Transmission Recall notice in the mail a few days ago, but he didn't read all the details, but he experienced the same issues as me. So I looked up recalls on the GM web site, and my VIN says that there are none. What is going on everyone and what can I do to fix this thing? I bought it to tow a trailer. I can't have it missing shifts. Thanks  Donnie  Sorry... I saw that I posted this in the Silverado Group by accident.