This is actually a fairly common problem on these vehicles. Most commonly, the Oil Pressure Switch loses it's internal resistance, and when at idle, reports a faulty reading on the oil pressure. Replacing the Oil Pressure Switch should solve the problem.
This is a job any local shop can handle. No need to go to the Dealer. You'll even save money by letting a local shop do the job, since they charge less for parts and labor. The switch will cost around $30 (give or take) and the labor isn't even an hour. Labor rates vary from shop to shop, so what you pay for labor will effect the botXXXXX XXXXXne.