What to do if my diagnostic link connector under the dash is not working? Also, will that trigger a check engine light?

It has to work unless we are talking about all 16 wires have been cut off. After plugging into the diagnostic port you are to turn the ignition key "On" to activate the communication between the reader and the car's computer. You do Not actually start the engine.

I have taken the care to two different places, followed the proper procedures and nothing.

That's unusual. Now I'm Clueless too. I hope it's nothing serious.

Me too!!

My scanner reads codes with key on, engine off. If there's a code, you get a freeze frame of data at time of the fault. Here, we are not looking for live data. Just trying to get the computer to talk. Live data comes key on, engine on.....that might be later.