I use this fluid & use a pump up style/pressurized chemical sprayer to inject it through the hole that is covered by the 5mm Allen plug.
I've used an OTC Genisys scan tool to check trans. Temp & also used an infrared heat gun...you have a temperature range to check it, so not very hard.
If you've lost enough fluid to slip transmission or not even move;you may want to pump some fluid in it before you start engine.
Be sure you are on level surface performing this...as the fill plug is actually called an overfill plug-designed to overfill & let it drain back out (while running) and will be a constant drip@the recommended temperature.
Fluid expands with heat,,,so it will appear low until it gets into the temp. Range.
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