Since day one I have had issues with my 8sp transmission in my 2014 V6 GC Limited 4x4 (current mileage 1100)...namely downshifts into 1st and 2nd were slow & rough, and sometimes I would even get a clunk from the drivetrain. In addition, the tranny seemed to hunt for gears at times, when I would floor the gas the transmission would hang in neutral for a few, and most the time the transmission did not seem to downshift quickly enough when taking my foot off the gas pedal.
So what I thought I'd try was "Reset" by means of a battery disconnect. I have powered seats, so...
1) I raised and moved forward the passenger seat as far as it would go.
2) I pulled off the battery cover on the floor under the seat (no tools required, simply stick your finger tips in there and pry/pull off). Only 4 tabs holds the cover on.
3) Then I disconnected the negative side of the battery, pumped the brakes to dissipate residual power in the system, and let it sit for 15 minutes.
4) Then I just reconnected the negative side, reinstalled the cover, put the passenger seat back down, and started the engine...letting it idle for about 5 minutes, then took it on a short 15 minute run around town. I DID NOT LOSE ANY UConnect settings, radio pre-sets, or any other interior settings
All I can say is WOW
...my GC is a totally different animal! It's now been two days, and the rough down shifts into 1st and 2nd are still gone, no more hunting for gears, when I floor the gas it finds a gear faster, and when I take my foot off the gas pedal, the transmission immediately starts to downshift.
I will be keeping my eye on this, and will report any new findings.