Diagnostic Aids

WARNING: This page is about a different car, the 2009 GMC Sierra and 2009 Chevrolet Silverado. However, it is still accessible from the selected car via links, so may be relevant.

A short to ground on the 2 high indicator control circuit will cause the 2 High indicator to remain ON at all times.
An open or high resistance will cause the 2 High indicator to be inoperative during the 2 second bulb inspection.
An open in the indicator dimming control circuit will cause the 2 High, AWD, 4 High and 4 Low mode indicators to be inoperative during the 2 second bulb inspection.