2003 Chevrolet Tahoe Owner's Manual - Page 192

Readings in the low warning zone may occur when a large number of electrical accessories are operating in the vehicle and the engine is left at an idle for an extended period. This condition is normal since the charging system is not able to provide full power at engine idle. As engine speeds are increased, this condition should correct itself as higher engine speeds allow the charging systemto create maximum power. You can only drive for a shorttime with the reading in either warning zone. If you must drive, turn off all unnecessary accessories. Readings in either warning zone indicate a possible problem in the electrical system. Have the vehicle serviced as soon as possible. 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 and a chime sounds there could be a brake problem. Have your brake system inspected right away. BRAKE 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. Brake System Warning Light With the ignition on, the brake system warning light will flash when you set the parking brake. The light will flash if the parking brake doesn't release fully. If you try to drive with the parking brake engaged, a chime will sound when the vehicle speed is greater than 3 mph (5 km/h). 3-41