i have a 2002 town and country it drives fine went to have it inspected the code p1684 is show but the check engine light is not on

Code is for power interruption to PCM, like if the car battery was dead. It's possible the bulb is burned out on the dash. Does light come on when you turn the key on right before you start it? Cars have readiness monitors which means you can't just clear a code and get a sticker, car has to be driven 50 miles without disconnecting power, then you can get a sticker

yes lights come on.i have not driven it a straight 50 miles with out turn the van off I have been driven it off and on the last three days

Doesn't have to be 50 miles in one trip, just 50 total

I just made sure if all the lights come on the dash. before I start the car and the check engine light do work.

ok, thank you very much.