A couple of weeks ago, we were in our 2011 Traverse and had the parking lights on. When we switched the headlights on, the driver side one would not turn on. The high beams would work on both sides, but not the low beams. I started simple by changing the bulb, but that did not work. Next, I checked the fuses and and replaced a relay. Still no dice. We were going to bite the bullet and take it to a mechanic to get it fixed when we realized that there was one thing we did not try. We ended up swapping the passenger side assembly and sure enough both lights worked. I ordered the driver side assembly and I am waiting to receive the part. Hopefully this saves someone some headaches as there was nothing on Google/YouTube that pointed us in this direction.