Patent ID: 7878932

Claim:
Method to monitor operation of an electro-mechanical transmission including a hydraulic circuit having a plurality of flow management valves and pressure control solenoids operative to actuate a plurality of clutches and a plurality of pressure monitoring devices adapted to monitor the hydraulic circuit, said transmission operative in fixed gear and continuously variable operating range states through selective actuation of the clutches, the method comprising: controlling position of one of the flow management valves, the one of the flow management valves adapted to selectively control operation of the electro-mechanical transmission in one of the fixed gear and the continuously variable operating range states; detecting a fault in the one of the flow management valves based upon outputs of predetermined ones of the pressure monitoring devices during steady state operation in one of the continuously variable operating range states; and, detecting a fault in the one of the flow management valves based upon the output of one of the predetermined ones of the pressure monitoring devices during a transition in the one of the flow management valves.