How can I fix a door adjar error on a 1999 Lincoln Continental? When the drivers door is shut, the warning comes on and the dome lights remain on. I don't want to spend money to replace the sensor, but can I bypass it?

I suspect you have a bad door ajar switch on one of your doors.

The switch is on the door latch. try pushing each door in with your hand one at a time and see if the warning goes away.
The Lighting control module is $500 and controls a lot of the vehicle functions. It is part of the headlamp switch. It has to be configured by the dealer with his NGS tester before it will work. Ebay has them cheap sometimes. Only buy Continental LCM for your model year.



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When at least one door is ajar and the key is in the RUN position, the door ajar cluster lamp is activated and remains on until all doors are closed. A warning tone will sound once any time the key is in the ignition switch and any door is open.
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Visual Inspection Chart Mechanical Electrical

• Door ajar switches.

• Fuse junction panel fuse 28 (10A), 4 (10A), 5 (10A).
• Power distribution box fuse 6 (60A).
• Circuitry.
• Damaged or corroded connectors.
• Lighting control module (LCM)
• Driver door module (DDM).
• Virtual image cluster (VIC).
• Restraint control module (RCM).
• Low tire pressure module.

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• The Door Ajar Chime Does Not Operate Properly

• LCM.
• Driver door ajar switch.
• Passenger door ajar switches.
• Key warning switch.
• Circuitry.

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remove the door trim panel to access the door ajar switch.


Remove the door open warning switch by turning it counterclockwise.
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Trim Panel —Front Door Removal

1. Remove the screw cover.

1. Remove the screws.

1. Remove the front door trim panel (23942) from the door.

1. Disconnect the electrical connectors and remove the front door trim panel.

Installation

1. Follow the removal procedure in reverse order.

Yes you can, its a simple switch, but price one as they aren't horribly expensive, even used on e-bay.

Common problem with these cars--Spray the internal latches liberally with WD-40 or similar product operate door several times and then spray with a silicone type spray--should solve your problem or, remove the leadwires to the switch, and shunt them, cover liberally in electrical tape and tuck into car body.