<P> The ignition switch does not carry the power to the fuel pump ; instead , it activates a relay which will handle the higher current load . It is common for the fuel pump relay to become oxidized and cease functioning ; this is much more common than the actual fuel pump failing . Modern engines utilize solid - state control which allows the fuel pressure to be controlled via pulse - width modulation of the pump voltage . This increases the life of the pump , allows a smaller and lighter device to be used , and reduces electrical load . </P>
how does a solid state fuel pump work
via pulse - width modulation of the pump voltage