Lately, my 2004 Chevy Trailblazer has been displaying the "Chk Oil" light when the vehicle first starts up for more than 20 seconds - much longer than the normal dash light test. Then is turns off and stays off until the next ignition. There is plenty of oil in the tank, and it looks clean.
I know how to reset the warning lights, but I want to make sure this isn't a symptom of a larger problem.