RAM 2013 CHASSIS CAB 3500 Owner's Manual page 46

44 THINGS TO KNOW BEFORE STARTING YOUR VEHICLE
To Lock The Vehicle's Doors
With one of the vehicle's Passive Entry RKE transmitters
within 5 ft (1.5 m) of the driver or passenger front door
handles, press the door handle LOCK button to lock all
doors.
Do NOT grab the door handle, when pressing the door
handle lock button. This could unlock the door(s).
Press The Door Handle Button To Lock