i have a 2003 2500 cr with the 48re trans, a few months ago the truck started unlocking and downshifting on the freeway and had irratic throttle, and i couldnt get over 30mph. the next day when it would rev high, the transmission was making noise so i had the transmission rebuilt he atated new od sol, governor and transducer, it drove fine for a week then the same issue but without the noise, its an intermittent problem. it will be fine and drive normal for a bit then be back to the same issues, i since then have replaced alternator, battery terminals and installed a bd noise isolator. im getting sick of spending money and the next step was going to be an apps sensor. Some help would be greatly appreciated.

 

Have you found what was wrong? I'm experiencing the same on my 2006 48RE.

 

Having the same issues when my truck shifts down out of OD. Just had my tranny rebuilt for the second time in 279,000 miles. I did have a code before I got the transmission rebuilt but I can't remember what code it was. I know I had the code read at O'rielly and they said I needed a throttle position sensor. I had them erase the code and haven't got it again since I had the transmission rebuilt but when it downshifts from OD to third it does not seem to have much power and seems to be kind of eratic.

 

you need to try the key trick (from off: forward back forward back forward) to get your own codes out of your pickups. With the symptoms you guys are describing, I can't imagine your trucks not throwing out multiple codes. you may not get the codes when it is "normal", but as soon as the symptoms show up, thats when I would pull over and do the key trick.

Just a suggestion, good luck