Is it the trans or something else?

[eaglesfly59]

My'04 when I step on brake put in drive rpm's rev up 1000 rpms and truck wants to take off in 2nd. But if I manually shift all gears work. Put back in park and engine idles normal. It is giving codes: P0602 and P0483. I should also mention that it has a Bully dog chip that has been stuck in tow mode for two years, and can't shut off. Any ideas? Diesel shop thought it was the ECM put a new one on and did the same thing, now they say I need a new transmission.
Makes no sense to me, went to work everything was fine went to go home and this started, I'm thinking some sensor or something, maybe TC is in lock up? Any help would be appreciated.

 

[p-Bar]

P0602 Control Module Programming Error/Not Programmed, P0483 Cooling Fan Speed. I would disconnect the bully Dog and get it back to stock to start with . Hate seeing mechanics throw parts at vehicle. Have you tried resetting codes? I would clean all your ground cable connections follow them off the negative post there are a few of them. Some others will chime in with more knowledge .

 

[Bob4x4]

sounds like a failing torque convertor.When it gets worse it can continue to add torque trying to maintain the correct idle speed,it can end up overpowering the brakes and push you through an intersection-not a good experience.Lots of the old programers would leave the p0602 code and give no symptoms.