Left headlight, brake light and turn signal do not work?

Yep, the BCM controls these functions but if you want to be sure you should do a CAN scan which will give you code for the BCM, you can get a CAN scanner (Controller Area Network) which will work on most cars from Amazon.

here is a video to show you how:

https://youtu.be/u-4syLc-ifQ

and

https://www.2carpros.com/articles/can-scan-controller-area-network-easy

Here is one for about $99.00 if you need it:

https://amzn.to/3ZixY4v

Here is how to replace the BCM, you can get a preprogrammed unit by searching Google or Ebay. Check out the images (below). Please let us know if you need anything else to get the problem fixed.