Just glossing over the 2009 Tacoma manual and noticed it says this:
Illuminates for about 3 seconds and then flashes
for about 12 seconds: Indi-
cates that the engine oil is
scheduled to be changed.
Comes on and remains:
Indicates that the engine
oil should be changed.
This seems to imply there is some kind of difference in how it determines when oil should be changed. I thought it went off mileage, but could it also be going by something else? Revolutions maybe?