Driving over 700 miles in 20 hrs yesterday (Las Vegas to Payson, AZ, and back) when, on the way back with about 450 miles in and on the highway at 90, I heard a beep. Looked down, and no idiot lights were on. Then I noticed that in the odometer (possibly trip odometer) window the numbers were gone, an oil can graphic was present, and next to it, it said "Hi" (not "high"). Stopped the car and while idling the graphic went away. I imagine that it meant that the oil pressure read too high momentarily, but could find nothing in the manual to even acknowledge that such a message was possible. What was this? Is it anything to worry about? What would cause this other than my guess? Thanks for any help.