P-0740 code for Dodge: is: Torque Converter Clutch Circuit Malfunction.If you have a scan tool, try to clear it, if it comes back clear it a second time, sometimes the code will stay in memory and reset the check engine lamp. If code continues, chech harness and plug at transmission, un-plug and plug back in, it could be just a dirty connection. I had this same problem after the local dealer serviced my transmission.
If you do not have a scan tool, BUY one ! Actron is a good one, easy to use and you'll be able to at least have some idea as to what's up with your vehicle "before" you take it in for repairs.
Good luck
Mike