I am not real familiar with transmissions that have as many sensors and computer connections as these have. I have a 2003 Avalanche 1500 4x4 and while driving home tonightit did not want to shift into 3rd or drive while easing into the pedal. If you get in the pedal it goes ok though.. Fluid level is fine but, vehicle seems to get hotter than it should. My wife usually drives this but what do your temperature gauges run at. Thanks in advance for any help..

 

I have a Yukon Denali and the engine runs at 200 to 205 degrees and the transmission temp gauge runs at 150 or so except in the winter when the trans temp barely moves off the scale.