I have a 2012 GMC Acadia Denali with approximately 8500 miles on it. I've experienced problems in the Tac reving to 4000 RPM after accelerating from a turn or red light going to green; the result of the transmission not shifting quickly enough to respond to the changing speeds. The Transmission Control Module was replaced because of an internal short and I had hoped that this was causing my problems. However the problem continues but cannot be reproduced at will. My dealer has been told about the problem but I've been unable to spend anymore time away from work to work with my dealer to diagnose the problem.