Three problems related to service brakes have been reported for the 2002 GMC Envoy. The most recently reported issues are listed below.
Driving at night and headlights on low beam and then they'll shut off.
For I have a 2002 GMC Envoy that is having brake problems and the answer that I was getting from the dealer was that my brakes were low, well I changed them and the problem is still there, for at times when holding down the brake the pedal will stop and then drop about an eight of an inch ( as if there is air in the lines) and I don't know if electrical problems are thought of as dangerous, but I have them too.
Consumer states while comiing down a hill pcm shorted out. As a result, driver lost all electrical functions. Steering wheel got really stiff. Brake pedal became hard to press.