2003 GMC Sonoma Owner's Manual - Page 160

Anti-Lock Brake System Warning Light With the anii-lock brake system, this light will come on when you start your engine and may stay on for several seconds. That's normal. Engine Coolant Temperature Gage 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 3-32. The anti-lock brake system warning light should come on briefly when you turn the ignition key to RUN. If the light doesn't come on then, have it fixed so it will be ready to warn you if there is a problem. United States Canada This gage shows the engine coolant temperature. If the gage pointer moves into the red area, your engine is too hot! It means that your engine coolant has overheated. If you have been operating your vehicle under normal driving conditions, you should pull off the road, stop your vehicle and turn off the engine as soon as possible. See Engine Overheating on page 5-30 for more information. 3-33