Probably a faulty on-off switch in the door jamb, or a misaligned door which fails to close the connection.
check the sensor on the door, its probably bad
If the switch is bad or out of adjustment, then the door ajar light will stay on. The overhead light will not go out, and the security alarm will not set.
some how the tail light wire is touching the ajar wire
On my 2002 sportage 2-door, the door ajar light stays on when the tailgate is not locked. with the key.
If the trunk lid isn't actually ajar, the switch has gone out of alignment, or it broke.
The back hatch may be ajar.
i had the same problem i just cut one of the wires leading to the switch that was causing the problem
Fix a "door ajar" on Chevy Impala 2003 . Still on doors closed.
Possible faulty door switch.Try contact cleaner or light grade of lubricant on the switch. Push it i nby hand and see if door ajar light goes out.
The trunk lid is open or the ajar switch has malfunctioned.The trunk lid is open or the ajar switch has malfunctioned.
It's not a question !
If the door is ajar and light stays on, spray some WD40 into the latch. The door switch is probably stuck. Spray all doors then open and close a few times.