How serious is it when the service tire monitor light comes on?
Check your tire pressure and can use a penny to see how deep the tread is and see if its wearing the same or if its damaged anywhere, belt broken, bulges ect.
It all depends on the vehicle you have. It could be a tire system fault, where your tire pressure sensors go bad, or your tire could actually be low. Some vehicles are more sensitive than others.
Search Chevrolet Cobalt Questions
Chevrolet Cobalt Experts
Related Models For Sale
Used Cars for Sale