Three problems related to headlights turn off while driving have been reported for the 2007 GMC Envoy. The most recently reported issues are listed below.
Headlights continue to go out while driving city streets and highway. Windows hesitate to go up and make a grinding noise. At times smells like smoke and then dissipates.
Headlights randomly shut off and won't come back on. High beams still work.
Headlights failed causing lights to go out while driving. Only the bright lights will work. Some kind of electrical malfunction. From my research, there have been many others.