2004 GMC Yukon Owner's Manual - Page 205

• If you move the shift lever to FIRST (1), the light will come on and stay on to indicate that the traction system is off. This is normal operation. To turn the system back on, move the shift lever back to a position other than FIRST (1); the light should go off. See Traction Assist System (TAS) on page 4-9. Engine Coolant Temperature Gage • 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, see Traction 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. 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 210°F (100°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 5-31. • If the vehicle is driven over an extremely rough road, the system will turn off and the light will come on. The light will go off a few seconds after the rough road conditions go away or when the vehicle comes to a complete stop. This is normal operation. 3-47