One problem related to starter solenoid has been reported for the 2006 GMC Envoy. The most recently reported issues are listed below.
Filled my gas tank up and the fuel gauge went to empty after filling. Every time I fill the tank, it goes to empty and then after driving a bit the gauge starts re-registering. I have no idea if it is accurate anymore. Evaporator purge solenoid has also went out causing the check engine light to come on. The lack of an accurate gas gauge is a safety issue. Please recall this vehicle.