Method and system for positive crankcase ventilation (PCV) diagnostics

A vehicle system comprising:

• a crankcase pressure sensor;
• and
• a controller with computer-readable instructions stored on memory that when executed, during a first condition, cause the controller to:
• execute a nominal crankcase pressure model corresponding to a crankcase location to determine a nominal crankcase pressure of a positive crankcase ventilation (PCV) system;
• execute faulted crankcase pressure model corresponding to the crankcase location to determine a faulted crankcase pressure of the PCV system;
• determine a difference between the nominal crankcase pressure and the faulted crankcase pressure;
• diagnose a PCV system component based on the difference between the nominal crankcase pressure and the faulted crankcase pressure;
• and
• responsive to the crankcase pressure sensor having a degraded diagnosis, generate a sensor degradation indicator.

A method for operating a positive crankcase ventilation (PCV) system, comprising:

• executing a nominal crankcase pressure model corresponding to a crankcase location to determine a nominal crankcase pressure of the PCV system;
• executing a faulted crankcase pressure model corresponding to the crankcase location to determine a faulted crankcase pressure of the PCV system;
• determining a difference between the nominal crankcase pressure and the faulted crankcase pressure;
• diagnosing the crankcase pressure sensor based on the difference between the nominal crankcase pressure and the faulted crankcase pressure;
• and
• responsive to the crankcase pressure sensor having a degraded diagnosis, triggering a sensor degradation indicator.