I keep getting that message. My front sidelight has a funny connection and does go out occassionally. This then registers on the computer. You cancel the warning (it will continue to show unless you do this) by pressing the front most button on the wash/wipe stalk beside your steering wheel (think it is called "S" or "R" but it's next to the button where you cycle through the display options). Check your bulbs and/or connections. [2001 Vectra 2.2 SRi]
Nebulaman, January 2007
