Diagnostic and control method for clutches in a vehicle system

A vehicle system, comprising:

• a transmission including a plurality of clutches configured to selectively engage and disengage to shift between a plurality of discrete gear ratios;
• a diagnostic controller or processing unit including:
• instructions that, when executed, cause the diagnostic controller or processing unit to:
• determine an engagement state of each of a plurality of clutches, wherein each of the engagement states are selected from a group of engagement states that include an engaged state, an intermediate state, and a disengaged state;
• and
• operate the vehicle system in a fault state based on a comparison of the engagement states of the plurality of clutches.

A method for operation of a driveline system, comprising:

• at a diagnostic controller independent from a driveline controller, determining a vehicle speed;
• determining an engagement state of each of a first clutch and a second clutch in a transmission based on a pressure or current associated with each of the first clutch and the second clutch, wherein the engagement state of each clutch is selected from a group of three or more clutch engagement states that includes an engaged state, an intermediate state, and a disengaged state;
• identifying an unauthorized clutch state based on a comparison between the engagement states of the first and second clutches and a set of unauthorized clutch states;
• and
• responsive to the identification of the unauthorized clutch state and the vehicle speed exceeding a threshold speed, operating the first clutch and the second clutch in a fault state.