oil low add oil

Change the oil every 5,000 miles regardless of what the dash gimmick says. Top off the oil to no more than a 1/2 quart low if you are driving to the oil change shop. 1/2 quart low is the limit for me.

When ever I buy a used car I change ALL the fluids and filters so I know the condition of everything. I also do a tune up which in your case is probably just spark plugs.

Also, To reset the light, turn the key to the position just before the vehicle starts. (when all system check lights lite up.) Press and Depress the gas pedal four times completely. Then turn the key all the way back, like you are gonna take your key out. Wait Two seconds. Then turn key to on position just before truck turns on. You should hear three ring tones.

Put oil in it before doing anything else .. then go back to where you bought it if u have any warranty

I have 2015 Tahoe and today I noticed a signal saying low engine oil. Is this a serious problem? what should I do?

Put oil in it. Vehicles burn oil especially when driven at higher rpms/ highway speeds. Your oil life is still at a higher life percentage. You've just burned off oil.