My 4.8is has the cold 1-2 shift bump issue as well as strange quick shifting when in D mode. No error messages, etc. If I let the car warm up for 3 minutes before driving, there is no 1-2 bump. I plan on having the fluid drained and filled as well as the sealing sleeve and "adapter" changed in a week or 2. I'll also have the transmission programming checked as well. Does anyone know what the proper up to date file for the transmission programming should be?