Trans low line pressure

[David Olsen]

2016 ram 2500 68 rfe Trans is slow to build pressure and move at start up. After that the Trans works fine no problems . If I try to move the truck before the pressure builds around 3 or 4 minutes I get a low line pressure code.
Please help I can't afford a total rebuild.

 

[Ozymandias]

I'd start with a filter and fluid service.