Selectable one-way clutch control

A method for controlling a selectable one-way clutch (SOWC) that is selectively engageable to connect a member of a planetary gear set to a stationary member of a transmission to thereby allow engine braking of a vehicle in a manual first gear, the vehicle having a transmission with the stationary member and the planetary gear set including a carrier member, a sun gear member, and a ring gear member, the method comprising:

• identifying a manual downshift command which is generated in response to an operator of the vehicle shifting from drive to the manual first gear;
• releasing an off-going clutch associated with a current gear ratio to thereby disconnect the sun gear member from the stationary member;
• increasing an engine speed after releasing the off-going clutch using electronic throttle control until a relative speed across the SOWC reaches approximately zero;
• engaging the SOWC after the relative speed across the SOWC reaches approximately zero to thereby connect the carrier member to the stationary member such that torque is held in both clockwise and counter-clockwise rotational directions across the SOWC and minimal impact load is absorbed during engagement of the SOWC;
• automatically reducing the engine speed after the SOWC is engaged such that the engine braking is enabled and the vehicle decelerates in the manual first gear.

A method for controlling a selectable one-way clutch (SOWC) that is selectively engageable to connect a carrier member of a planetary gear set to a stationary member of a transmission to thereby allow engine braking of a vehicle, the method comprising:

• identifying an operator commanded downshift requesting a manual downshift from second gear to a manual first gear;
• releasing an off-going band clutch associated with second gear to thereby disconnect a sun gear member of the planetary gear set from the stationary member;
• increasing an engine speed using electronic throttle control until a relative speed across the SOWC reaches approximately zero;
• engaging the SOWC to thereby connect the carrier member to the stationary member after the relative speed across the SOWC reaches approximately zero such that minimal impact load is absorbed during engagement of the SOWC;
• reducing the engine speed after the SOWC is engaged such that the engine braking is enabled and the vehicle decelerates in the manual first gear;
• and
• releasing the SOWC after the engine braking is complete.