A diagnostic system for a pressure sensor includes a fuel pump module and a diagnostic control module. The fuel pump module activates a first pump and deactivates a second pump when an engine is operating in a diagnostic mode. The first pump supplies fuel to the second pump and the second pump supplies fuel to fuel injectors of the engine via a fuel rail. The diagnostic control module receives a measured pressure signal from a pressure sensor that indicates a pressure of the fuel rail during the diagnostic mode. The diagnostic control module detects a fault of the pressure sensor based on a comparison between the measured pressure signal and the commanded pressure signal for the first pump.