2003 GMC Sierra 1500 Pickup Owner's Manual - Page 197

The traction off light may come on for the following reasons: If you turn the system off by pressing the TAS on/off button located to the left of the steering wheel the light will come on and stay on. To turn the system back on, press the button again; the light should go off. If you move theshift lever to FIRST (l), the light will come on andstay on to indicate that the traction system is off.This is normal operation. To turn the system back on, move the lever back to a shift position other than FIRST (1);the light should go off. See TractionAssist System (TAS) on page 4-9. The light will come on and stay on if the TAS automatic engagement feature has been turned off. To turn the system on,press the TAS off/on button; the light should go off. To turn the automatic engagement feature back on, seeTraction Assist System (TAS) on page 4-9. If the Traction Assist System is affected by an anti-lock brake system, TAS or engine-related problem, the system will turn off and the light will come on. Have your vehicle serviced. If the vehicle is driven over an extremely rough road, the system will turn off and the light will come on. The light will gooff a few seconds after the rough road conditions go away or when vehicle comes to a the complete stop. This is normal operation. Engine Coolant Temperature Gage ~~ United States Canada This gage shows the engine coolant temperature. It also provides an indicator of how hard your vehicle is working. During a majority of the operation, the gage will read 21 0°F (1 00°C) or less.If you are pulling a load or going up hills, it is normal for the temperature to fluctuate and approach the 250°F (122°C) mark. If the gage reaches the 260°F (125°C) mark, it indicates that the cooling system is working beyond its capacity. See Engine Overheating on page 5-36. 3-42