Hi Thank you for using Just Answer, I am afraid that the cable drive which opens your tailgate has broken. Basically there is an electric motor which pulls a cable that is attached to your latch assembly. The cable has a tendency to break at the connection to the electric motor..So you will hear the motor run but nothing will happen.
The only way into the tailgate to repair this problem is to force the carpet panel down (which can cause damage) to gain access to the cable and release the latch. And then the latch assembly will need to be replaced.
I hope this helps, if you need anything clarified just reply back and I will do what I can to help.
I need to know how to fix the problem , I already know what the problem is.