i have an 07 cummins with the 5.9 and 48re. i had a cracked overdrive, changed that, changed my governor pressor solenoid,Borg Warner Pressure Solenoid andOverdrive & Lock-up Solenoid Assembly. truck was working fine for a month and now i am getting the code p0973 and it puts the truck in limp mode and stays in 3rd gear. i was able to clear the code and it would work fine for around 50 miles. now when i clear it it comes back on within 10 miles. i checked all the fuses and they are all good, i unplugged the main plug on the trans and plug it back in, seems good. not sure whats wrong. could one of the solenoids be bad? any help would be great i miss driving my truck!

 

Sounds like a solenoid or a wire to the solenoid. Maybe during the OD maintenance a wire came loose inside the pan? Hows the fluid level?
The diagram below may help.

2007 Dodge trans.pdf

2007 dodge trans diagram.pdf

 

it ended up being a faulty OD Solenoid, changed it and drives great!