Fuel pump relay (FPR) is a small electrical device of a vehicle’s fuel delivery system. FPR is also known as relay switch. FPR is designed to control the supply of power to the fuel pump and makes sure that enough power is supplied. FPR is very essential for optimal functioning of fuel delivery system.
Before knowing where the FPR is located, let us first know how it looks. FPR is a small part in a plastic case. It has several sprockets that attach the relay to the ignition assembly.
The exact location of the FPR varies based on the car model. If you want to find its location, check your vehicle owner’s manual. A few common locations where you can find the FPR are, the car’s internal firewall, fuse box under the hood, underneath the dashboard, on one of the fender covers, or near the steering wheel.
Function and working of FPR
As mentioned earlier, the main function of FPR is to act as a conduit that supplies and controls the power supply. The FPR is controlled by an engine control module (ECM).
When you start the vehicle, the FPR turns on the fuel pump. Once the engine starts running, the FPR shuts off. During this time, power is supplied by the oil pressure sending unit. The FPR comes into picture once you switch off the ignition. Once the ignition is turned off, the FPR will shut off the fuel pump.
Importance of FPR
The FPR is a powerful component of a vehicle’s fuel delivery system. It requires plenty of power to function optimally. Even though it is designed to handle significant amounts of power, too much current may damage its delicate wiring and can even damage the fuel pump. Thus, by controlling the amount of power supplied, the FPR protects it from getting damaged.
Signs of a bad FPR
The main function of the fuel pump is to draw the fuel from fuel tank and supply it to the ignition system. Its normal functioning may get affected and you may experience some trouble using your vehicle if there is something wrong with FPR.
The primary symptoms of a bad FPR include – the engine will crank up, but won’t start, there will be delay in starting and the fuel pump will not switch on. The car loses power while driving and the sound will be different when your vehicle is switched on.