Dashboard indicator for failed exterior light

Have you checked reverse lights, brake lights, license plate lights?

Yes. All exterior lights visually check good.

This vehicle appears to have a light control module that senses current flow through the exterior lamp circuits. Improper current flow appears as a bad bulb to this module. Has anyone replaced any bulbs recently? An incorrect bulb...though working....could trigger this problem. CORROSION/BAD CONNECTIONS at any of the bulb sockets could also trigger the warning light. Finally...a bad (very expensive) Module could be the cause. Suggest you do the cheapest thing first. Turn on your exterior lights and with someone in the vehicle...operate BRAKE/DIRECTIOAL/HAZARD lights and carefully check for consistent brightness throughout. Make sure that brake light in the rear window functions at the correct brightness. Also...check you license plate lights carefully. I usually lightly smack these lights with the palm of my hand to initiate a malfunction. Good Luck.

http://www.nhtsa.gov/.......Seems there was a problem with aftermarket replacements of exterior lamps on your vehicle. We sometimes have to replace bulbs with OEM types for a trouble free repair. Might be worth checking the manufacturer of your existing lamps. Since your vehicle is about 15 years old...it may have had several lamps replaced. Again ....Good Luck.