Engine cut out on the highway, cranks but will not start?

Hi everyone,

I encountered a serious issue with my BMW 523i while driving on the highway. Out of nowhere, the engine cut out while I was cruising, and now the car cranks but does not start. Here are the details:

Event Details:
The engine suddenly shut off without any prior warning or dashboard indicators. Immediately after, I tried to restart the car—it cranks, but it fails to fire up.

Preliminary Checks:
• I’ve verified that the battery voltage is normal, and all battery connections are secure.
• There were no warning lights or error codes observed on the dashboard at the time of the incident.

Suspected Areas:
• Fuel Delivery: I’m considering the possibility of a failing fuel pump or a malfunctioning fuel pump relay, which might have interrupted fuel supply.
• Ignition System: There is a chance that an ignition component such as the crankshaft position sensor or the ignition control module has failed.
• Electrical Issues: I suspect there might be a wiring fault or a loose connector affecting the engine control module (DME).
• I haven’t yet scanned the car for diagnostic codes, but that is my next step.

Any suggestions on further diagnostic steps or known issues with this model would be greatly appreciated. If anyone has experienced a similar problem or has tips on troubleshooting these symptoms, please let me know.