First of all that code is P0740 not PO740 or Po740, meaning that after that P they are all numbers. That might help in the future if doing an internet search and you have no search results.
Now, with that done said the P0740 refers to a transmission torque converter that does not lock or unlock properly.
First thing to do is check the transmission fluid level.
Here is a troubleshooting procedure.
Images (Click to enlarge)
Friday, November 24th, 2017 AT 7:03 AM