Fuel rail pressure sensor diagnostic techniques

摘要

A first computer-implemented diagnostic method can run in response to an imminent deceleration fuel cutoff (DFCO) event. A second computer-implemented diagnostic method can run on engine shutdown. Both diagnostic methods involve controlling fuel injectors and a fuel pump to make the fuel rail pressure change from a desired minimum to a desired maximum. Measurements from the fuel rail pressure sensor at these endpoints can then be used to detect a fault of the fuel rail pressure sensor. One or both diagnostic methods can be implemented.

主权项

1. A method, comprising:
detecting, at a controller for an engine, the controller having one or more processors, an upcoming deceleration fuel cutoff (DECO) event; and executing, by the controller, a first diagnostic routine for a fuel rail pressure sensor in response to detecting the upcoming DECO event, the first diagnostic routine including:
deactivating a fuel pump;commanding fuel injectors to inject fuel into the engine to decrease a pressure in a fuel rail to a desired minimum pressure;receiving a first measured fuel rail pressure from the fuel rail pressure sensor;deactivating the fuel injectors;reactivating the fuel pump;commanding the fuel pump to supply fuel to the fuel rail to increase the fuel rail pressure to a desired maximum pressure;receiving a second measured fuel rail pressure from the fuel rail pressure sensor; anddetecting a fault of the fuel rail pressure sensor based on a pressure difference between the second and first measured fuel rail pressures.