If all the doors are shut tight you probably have a broken or out of adjustment door switch.
Those are actuated by a switch in the door frame... most likely, you either have a defective switch, or a short to power elsewhere in the circuit.
On my 2002 sportage 2-door, the door ajar light stays on when the tailgate is not locked. with the key.
spray your door latches with wd40.
bad door ajar switch inside one of the doors its in the striker assy
If your interior light is also on, replace the door switch.
some how the tail light wire is touching the ajar wire
I've had that happen in my 2002 mountaineer. what I've found is that if you spray the door latches with wd40 it will clean off the sensors and the door ajar light should go out. but make sure all the doors are shut.
i...i dont know. do you?
If the trunk lid isn't actually ajar, the switch has gone out of alignment, or it broke.
If the door ajar light is coming on in your gauge cluster, and the warning chime is sounding when all your doors, liftgate, and glass hatch are securely shut you most likely have a sticking door ajar switch. The door ajar switches are inside the doors mounted on the latch mechanisms.
The back hatch may be ajar.
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.