fixed period. If vacuum cannot be built into the system, or if the system will not hold a vacuum, a leak isevident. A signal fuel level input (FLI) sensor is usedduring the leak check to determine how much fuel isin the tank. This determines how long it should taketo build a vacuum in the tank. The FLI input is alsoused to determine if the EVAP and other monitorscan run. Too low or too high of a fuel level will notallow the monitors to run.On systems with an LDP, the PCM turns on thepump when it is checking the system. The pump