Your 2006 GMC Envoy has an onboard diagnostic computer that will store trouble codes when there is something wrong with the vehicle's emissions control system. The emissions system is important and if it is malfunctioning, it can dramatically affect the performance of the Envoy's engine. Once you've fixed the vehicle, you need to know how to reset the check engine light. To do this, you need a special tool available at most auto parts stores called an OBD scan tool. The scan tool will have a feature that allows you to erase all stored engine codes, which will reset the check engine light.
Locate the open OBD port to the left of the fuse panel in the driver's side foot well.
Plug the OBD scan tool into the open port.
Turn the ignition to the "II" position (the "on" position), but do not try to crank the engine.
Press "erase" on the scan tool to erase all computer codes and reset the check engine light.
