2009 Jeep Patriot check engine light on, no code on 2009 Jeep Patriot

Do you need to turn the car on to get the code? Or can it register with just power on? I had someone put the diagnostic machine on to read the code, but he did not turn the engine over.

Asked by for the 2009 Jeep Patriot
1 answer
NO POSS NEEDS A BETTER SCANNER TO RETRIEVE CODES