How do I know if my shift solenoid is bad

What is your question?

RPMs and engine seem fine but going up hills car won’t go out of second gear and appears to be stuck in limp mode. Saw on a forum that I should change the shift solenoid pack. Any other suggestions?

What makes this problem better or worse?

Nothing

How long has your 2005 Dodge Ram 1500 had this problem?

Weeks