Patent ID: 7867135

Claim:
Method for redundant fault detection in an electrically variable, hydraulically controlled transmission operative to transmit mechanical power flow originating from an engine and electric machines to an output member through selective application of torque transfer clutches, comprising: monitoring hydraulic pressures within a hydraulic control circuit configured to selectively apply the torque transfer clutches, detecting therefrom a mismatch between a commanded clutch state and an actual clutch state, and executing a first remedial control operation upon the detecting of a mismatch between a commanded clutch state and an actual clutch state associated with the monitored hydraulic pressures within the hydraulic control circuit; and monitoring rotational speeds of the electric machines and the output member, detecting therefrom a mismatch between a commanded clutch state and an actual clutch state, and executing a second remedial control operation upon the detecting of a mismatch between a commanded clutch state and an actual clutch state associated with the monitored rotational speeds of the electric machines and the output member.