Chevrolet,Power steering warning came on?

Tried to use wipers this morning, warning light came on that said "power steering" then wipers wouldn't work. Drove it to work, came out after work and wipers worked and the warning wasn't showing anymore. I'd like to know what it could possibly be. There is no whining noise when i turn the wheels to indicate anything is wrong with my steering. I am aware now that Chevy Cobalts have electric steering and do not take power steering fluid.

My car has 135000 miles.
My car has an automatic transmission.