How to fix a stalled engine in an Audi A4?

My Audi A4 recently stalled while I was driving and won't start again. The dashboard lights are still on, so it doesn't seem to be a dead battery. What could be causing this issue and how can I fix it?

First, try checking the fuel pump and fuel filter. A clogged filter could be preventing proper fuel flow to the engine, causing it to stall. If that doesn't solve the issue, it could be a problem with the ignition system. Consider getting a diagnostic test done at a mechanic to pinpoint the exact issue.