I would get check the battery first because low voltage issues do cause erroneous codes and errors. Secondly, the oil pressure light does not flash as far as I know, it is a steady light as is the overheat or the check engine light, when they are individually illuminated. Flashing occurs when the no wake mode is engaged and all three lights flash. And then when you get a pattern flashing, it is giving you a code. The warning system will also reduced engine speed to 3000 rpm if either, the oil pressure does not rise to what is required, or if the engine overheats. If your engine speed was not reduced to 3000, that is an indication also that it is not the oil pressure warning. In the sunlight or even in the dark, those lights can be confusing as to which one is actually illuminated. But flashing is reserved for no wake mode operating, and for code delivery. Here is a listing of engine codes that are flashed. Note that it flashes one digit, then pauses, then flashes the other digit. I may be wrong, but I thought the light that flashed when an engine code is generated, is the check engine light, the first light on the left. Note the first picture I posted of page 2-13, at the bottom left of the page, it shows the 3 lights in the cluster and their corresponding meaning.