I believe that would be your "maintenance due" light. Most GM vehicles as of 2005 or so have a program built in to the vehicles computer that will let you know when it is time for your normal service to be performed. It measures this by how many times the vehicle is started, how long it is run for, etc. Sometimes it will come on after 3000 miles, sometimes 5000 miles and sometimes more. GM says that once the light comes on, they recommend you have an oil and filter change and any other necessary work done within 500 miles of the light illuminating. On average the light will come on about every 5000 miles but it can go to 8000 miles. I would suggest no matter what that the oil and filter be changed every 8000 miles at most with regular and not synthetic oil. You can always do the service sooner than that. Transaxles should be serviced at 30,000 miles or less on front and all wheel drive models on the Equinox. Please rate me on this answer.