Fuel pressure sensor error within identification range

Abstract

This application relates to identifying in-range fuel pressure sensor errors. Methods and systems are provided for diagnosing errors in the range of a pressure sensor disposed downstream of a lift pump in a fuel system of a vehicle. In one example, a method includes: performing feedback control of a lift pump based on an output of a pressure sensor; monitoring the pressure sensor output for flattening during an applied voltage pulse; and depending on whether the pressure sensor output is flattened by at least one The threshold duration, which is indicative of an in-range error, adjusts the operation of the fuel system. The method also includes dynamically learning a setpoint pressure of a pressure relief valve of the fuel system and a fuel vapor pressure within the fuel system by monitoring the pressure sensor output while adjusting a duty cycle of a voltage pulse applied to the lift pump.

Description

technical field [0001] The present description generally relates to methods for diagnosing an in-range error in a pressure sensor disposed downstream of a fuel lift pump in an internal combustion engine and adjusting fuel system operation in response to the diagnosis. Background technique [0002] An internal combustion engine may include a fuel system having a fuel rail for distributing fuel to one or more fuel injectors, which may be direct injectors and / or port injectors. In fuel systems operating with direct injectors, a fuel lift pump supplies fuel to a high pressure fuel pump which in turn supplies fuel to a fuel rail at a high injection pressure. The fuel rail is coupled to direct injectors that inject fuel directly into the engine's combustion chambers. In fuel systems operating with port fuel injection, the fuel lift pump supplies fuel to the fuel rail at lower injection pressures. The fuel rail is coupled to a port injector that injects fuel into an intake port o...

AI Technical Summary

Problems solved by technology

However, a degraded pressure sensor can read higher or lower than the actual pressure and still respond to pressure fluctuations

Furthermore, by only providing enough fuel to drive the vehicle out of danger or to a service center after pressure sensor degradation is identified, desired vehicle operation is not available when pressure sensor degradation occurs, which can negatively impact driver satisfaction

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