l have been trying to start my BMW this morning.It just cranks but wont start. l can see a yellow symbol on the dashboard.Any idea?

Need more info. What kind of sound is it making? A clicking sound, no sound at all??

With the little amount of info you supplied, my guess would be a dying battery. Pretty soon you will notice that if you try and start it again that it will no longer crank. The yellow symbol. l am assuming that its an indicator of something not getting power.not sure which indicator though. But you should jump start your car.and then go get a new battery.