The keyless entry is separate from the overhead "welcome back" light.
On your 2011 Landmark, the overhead light is probably a fluorescent fixture. The switch on the fixture has to be ON.
You also should have a rocker switch labeled "aisle" inside your control panel. For the "welcome back" feature to work, this switch must be OFF.
If you turn the "aisle" switch ON, the light should come on and stay on. If it doesn't come on, you probably have the lamp fixture switch OFF or there's a problem with the bulbs.
If the "aisle" switch is OFF, and the fixture switch is ON, and it doesn't work, you may have a problem with the switch inside the door threshold or with the wiring.
I've attached a preliminary wiring diagram that shows the system at rest, with the "aisle" switch ON, and with the "aisle" switch OFF and the Door Switch activated. I think the diagram is accurate, but it hasn't been verified.