My 2004 bmwx3 won't start. Dash board lights up and fuses and key are good. Would it have anything to do with the master flow sensor?

SOURCE: My 2004 530i won't start.

If you hear a mechanical hum then its either something with the starter or the battery. Charge your battery and see if its just a little too weak to turn the engine over. If that doesnt fix it, then you might have to replace the starter. Unless there is a serious mechanical issue, your engine shouldnt be the reason the starter can't get it to turn over.

SOURCE: 1998 bmw 740il will not start even with new a battery

If you checked all the fuses try putting the car in neutral sometimes the shifter gets misadjusted and wont start till the car is completely in park.If not check for a lose wire to the starter.If the car has an after market alarm you will have to turn it off before starting there should be a little buuton under the drivers dash or kick panel.GOOD LUCK

SOURCE: with my bmw318i 1997.i have difficulty starting

look for bad grounds in the ignition circuit.the corrosion is creating a voltage drop,but time and heat decrease the resistance..

SOURCE: bmw no power

You need to replace your ignition switch.

SOURCE: My 1998 bmw 528i won't start , I got dash light ,

all those problem have to do with modules on the vehicle have the car electronically scann and it will tell you where and what