2005 GMC Canyon Owner's Manual - Page 155

When the ignition is on, the brake system warning light will also come on when you set your parking brake. See Parking Brake on page 2-29 for more information. The light will stay on if your parking brake does not release fully. If it stays on after your parking brake is fully released, it means you have a brake problem. 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 the pedal 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 4-50. Anti-Lock Brake System Warning Light With the anti-lock brake system, this light will come on briefly when you start your engine to show it is working. Then it will turn off. This is normal. {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 stays on, or comes on when you're driving, your vehicle needs service. If the regular brake system warning light isn't on, you still have brakes, but you don't have anti-lock brakes. If the regular brake system warning light is also on, you don't have anti-lock brakes and there's a problem with your regular brakes. See Brake System Warning Light on page 3-28. The anti-lock brake system warning light should come on briefly when you turn the ignition key to ON. If the light doesn't come on then, have it fixed so it will be ready to warn you if there is a problem. 3-29