Method and apparatus to monitor an on-vehicle fluidic subsystem

A fluidic subsystem disposed on a vehicle, the fluidic subsystem comprising:

• an electric motor electrically connected to a motor driver and rotatably connected to a fluidic pump that is disposed in a fluidic circuit that is monitored by a pressure sensor;
• a current sensor disposed to monitor direct current (DC) current supplied to the motor driver;
• a controller, in communication with the motor driver, the pressure sensor and the current sensor, the controller including an instruction set that is executable to:
• dynamically observe operation of the fluidic subsystem;
• determine a plurality of observed parameters associated with the operation of the fluidic subsystem, including a direct current (DC) voltage level of the motor driver, an observed pulsewidth-modulated (PWM) duty cycle to the motor driver, a DC current flow to the motor driver, an observed motor speed of the electric motor, an observed fluidic pressure, an observed fluidic flow in the fluidic subsystem, and a DC-equivalent motor resistance for the electric motor that is determined based upon the DC voltage level, the PWM duty cycle, the observed motor speed, and the observed DC current;
• determine a plurality of estimated parameters associated with the fluidic subsystem;
• determine a plurality of fault isolation parameters based upon the plurality of observed parameters and the plurality of estimated parameters;
• isolate a fault in the fluidic subsystem based upon the plurality of fault isolation parameters;
• and
• communicate the isolated fault.