There are a few places a problem like this could be created. The most common would be the High beam relay in the underhood fuse block. This relay is labeled as HDLP HI-BEAM relay #56. If this relay is stuck it would allow for the problem you are having. There are other items that could cause for this and they would be the turnsignal/dimmer switch, or the wiring from this switch to the relay. There are some wiring tests that could be done, but you will need a voltmeter to do them. Here is a wiring schematic so that you can see how the system is wired. Feel free to contact me with any questions or problems! Good luck!
The body control module is located underneath the center console.