2005 Chevrolet Impala Owner's Manual - Page 150

Charging System Light The charging system light will come on briefly when you turn on the ignition, but the engine is not running, as a check to show you it is working. Brake System Warning Light Your vehicle's hydraulic brake system is divided into two parts. If one part isn't working, the other part can still work and stop you. For good braking, though, you need both parts working well. If the warning light comes on, there is a brake problem. Have your brake system inspected right away. It should go out once the engine is running. If it stays on, or comes on while you are driving, you may have a problem with the charging system. It could indicate that you have problems with a generator drive belt, or another electrical problem. Have it checked right away. 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, such as the radio and air conditioner. United States Canada This light should come on briefly when you turn the ignition key to RUN. If it doesn't come on then, have it fixed so it will be ready to warn you if there's a problem. 3-30