It is the consistent pressure the Chevrolet Electric Fuel Pump provides the new fuel injection system so it can perform at their peak efficiency. This is a requirement for the specifications of the new type of engines that are rolling off of the assembly lines.
The electric fuel pumps on Chevrolets now being produced are located in the fuel tanks of the vehicle. At this position they are in place to push the fuel to the intake system of the engine in the front of the vehicle. This is the opposite in the way the older style of mechanical fuel pumps operated. They sucked the fuel the fuel up to the front section of the vehicle. This leads to a less reliable and consistent flow of fuel.
To replace the electric fuel pump on the newer Chevrolets does require the fuel tank to be lowered and removed from the vehicle. This is a more time consuming procedure than the mechanical fuel pumps, but occurs less often since there is no diaphragm to wear out in the electric fuel pumps like the older mechanical ones had.
Before the electric fuel pump is replaced, the owner of the vehicle should remember to remove the ignition key. This way it is assured that the power to the pump is off. If the key is in the on position, the Chevrolet electric fuel pump will be active and creating pressure in the fuel lines which could cause a spray of fuel on the technician when the seal is broken to remove the pump. The Chevrolet owner should also remember that with the key on pressure is in the fuel system when they decide to change the fuel filter. This will prevent any pressurized fuel from being spayed that could cause a hazardous situation to occur.