Mystery problem

no codes - idle goes up and down, also speedometer sometimes moves when idleing in gear also sometimes shakes car amd hesitates while driving down road, sometimes when car has been shut of and key is out and go to lock doors it acts like the key is in the switch and unlocks doors. also key is accessories position listening to radio, and suddenly shut off radio, have to turn off key and turn it back on to hear radio again. already replace module behind ignition switch.

What is the year make and model of your car?

2003 mercury sable gs