I have 2001 S40 ~40K miles. Regularly maintained by dealership.

Today, I cannot get engine start. When I push brake (before start engine), I hear some buzz noise, it lasts for 5 secs. Start engine does not work, but power is on. Also "check engine" and "oil light" is on.
Battery is 2.5 yr old, should be fine.

I check the engine oil level is fine. The coolant is a little bit lower than minimal. Maybe coolant refill might not be part of regular maintenance.
Every other fuild level is fine.

What could be wrong, and how do I know the "check engine" code without towing my car to the dealership?

Thanks in advance