1997 GMC Sonoma Owner's Manual - Page 111

Shift Light You have the SHIFT light if you have a manual transmission. This light comes on very briefly as a bulb check when you start the engine. Shifting when the indicator light is on will help you get the best fuel economy. See "Shift Light" in the Index. Check Gages Light The CHECK GAGES light will come on briefly when you are starting the engine. SHIFT CHECK GAGES Daytime Running Lamps Indicator Light :::O 0.0 This light is on the instrument panel. It goes on whenever the DRL are on, the ignition is on, the headlamp switch is off and the parking brake is released. If the light comes on and stays on while you are driving, check your coolant temperature and engine oil pressure gages to see if they are in the warning zones. 2-63