2009 2500 Dodge Diesel Auto Tran 4x4
 

I have a PPEI tuner installed which I don't think is causing my problem.
My transmission when in tow haul mode is not shifting properly. It goes from 1st to 4th gear skips 2&3. Luckily I was close to home. Reflashed then it works until next time. It's only happened 2 times. Any help is appreciated!