The automatic transmission on my 2015 Toyota Tacoma is a closed system. It doesn't even have a dipstick. You check the fluid level by parking on a flat surface and draining fluid from the pan from a screw in the bottom of the pan. Above the drain screw is a little straw that sticks up a couple inches into the pan, the top of which equals the "full" level. The engine must be just below operating temperature for volume measurement to be accurate. Checking the fluid level this w