2008 GMC Sierra 1500 Pickup Owner's Manual - Page 178

This light should come on briefly when you turn the ignition key to RUN. If it does not come on then, have it fixed so it will be ready to warn you if there is a problem. Antilock Brake System Warning Light For vehicles with the Antilock Brake System (ABS), this light will come on briefly when you start the engine. {CAUTION: Your brake system may not be working properly if the brake system warning light is on. Driving with the brake system warning light on can lead to an accident. If the light is still on after you have pulled off the road and stopped carefully, have the vehicle towed for service. If the light comes on while you are driving, pull off the road and stop carefully. You may notice that the pedal is harder to push or may go closer to the floor. It may take longer to stop. If the light is still on, have the vehicle towed for service. See Towing Your Vehicle on page 4-41. That is normal. If the light does not come on then, have it fixed so it will be ready to warn you if there is a problem. If the ABS light stays on, turn the ignition off, if the light comes on when you are driving, stop as soon as it is safely possible and turn the ignition off. Then start the engine again to reset the system. If the ABS light still stays on, or comes on again while you are driving, your vehicle needs service. If the regular brake system warning light is not on, you still have brakes, but you do not have antilock brakes. If the regular brake system warning light is also on, you do not have antilock brakes and there is a problem with your regular brakes. See Brake System Warning Light on page 3-41 For vehicles with a Driver Information Center (DIC), see DIC Warnings and Messages on page 3-59 for all brake related DIC messages. 3-42