The early type dash was diffrent, they would flash sometimes, where as none of the later ones did unless it was low pressure or another non start fault. I have never noticed if ALL the older dial moduls did it, but i know a few of mine did, but i have never seen a new style module doing it unless its been cranked for a while. On constantly is self test, flashing is oil pressure, possibly the early type just didnt have the self test stage.