A fuel tank pressure sensor is a small device that resides in an automobile's fuel tank that measures the pressure within the tank. It uses this information to alert the vehicle's internal computer when there is a leak in the fuel system.
The fuel pressure sensor works in conjunction with a vehicle's evaporative control (EVAP) system, which captures any evaporated fuel before it leaves the fuel system. The sensor alerts the vehicle's computer to not only fuel tank leaks, but also to leaks in the EVAP system.
The fuel tank pressure sensor is always monitoring the pressure in the fuel tank for potential leaks. Pressure testing in the EVAP is performed periodically, typically after the vehicle has been sitting for a while (e.g., when the vehicle is first started up in the morning).
Monitoring for leaks in the fuel tank and EVAP system can help vehicle owners recognize and repair leaks as soon as they begin occurring, saving fuel -- and gas money. It also helps vehicle owners to stay in compliance with federal and state regulations regarding emissions from fuel systems.
