Knowing how your car's fuel pump operates is always helpful, but here are very convenient ways to check if it is broken or has stopped working.

So, despite the input voltage, it regulates to an exact output voltage, either what is preset or what a controller (the engine computer or Fuel Pump Driver Module) commands.

The typical returnless system uses a fuel rail pressure sensor, along with other typical engine sensors, to work with the ECM and a fuel pump controlled by a fuel pump driver module.