My check engine light is on when I push button for code it does not blink help

What is your question?

In the small box under the hood I push down and hold button for 30-60 seconds but the light does not blink for a code to tell me what the problem is .i replaced the old gas cap. Also it's a sportline edition with 120,000 miles excellent condition in and out. Someone please help me out this is my baby