My transmission quit shifting last night out of the blue. All I have is 3rd in drive and 2nd If I manually shift. I drained the fluid for the second time in 4 days and it worked when I test drove it until the next morning. I kinda think it's something simple like a sensor. It was never slipping or acting up before. I have P0700 &P0750 codes. I have read about this problem but the fix was different in each case. I'm going to replace the trans pressure switch and the input, output sensors. That's the only thing I have changed in the past. I am going to troubleshoot with my old parts before I start throwing that Dodge money at it. 2006 Dodge Ram 1500 SLT 2wd 5.7 545RFE.