The charging system light will come on briefly when you turn on the ignition, and the engine is not running, as a check to show you it is working.

Then it should go out when the engine is started.

If it stays on, or comes on while you are driving, you may have a problem with the electrical charging system. Have it checked by your GM dealer. Driving while this light is on could drain your battery.

If you must drive a short distance with the light on, be certain to turn off all your accessories.