A programmable lock cylinder assembly comprising: a lock housing having a body defining a tubular opening; a cylinder plug having a body mounted for rotation within the tubular opening, the cylinder plug including a keyway extending therein; at least one locking member in the cylinder plug and moveable between a locked position wherein the cylinder plug is rotationally locked relative to the housing and an unlocked position wherein the cylinder plug is rotational relative to the housing, wherein the at least one locking member includes a sidebar biased radially outward and received in a groove (225,227) along the lock housing In the locked position; a plurality of pin sets, each pin set including a keyway pin component and a locking pin component and positioned in the cylinder plug such that a portion of each keyway, pin component extends across the keyway, each keyway pin component selectively engageable with a respective locking pin component; a re-combinating member engaged with one of the components of each pin set and moveable between a first position wherein the keyway pin components are engaged with the locking pin components and a second position wherein the keyway pin components are disengaged from the locking pin components; and a reset actuator positioned within the cylinder plug with a portion aligned with the keyway, the reset actuator moveable between an engaged position wherein the re-combinating member position is locked relative to the cylinder plug and a non-engaged position wherein the re-combinating member position is moveable relative to the cylinder plug; characterized in that: each locking pin component includes a rotatable toothed gear defining a locking sidebar notch configured to receive the sidebar In the unlocked position. a lock housing having a body defining a tubular opening; a cylinder plug having a body mounted for rotation within the tubular opening, the cylinder plug including a keyway extending therein; at least one locking member in the cylinder plug and moveable between a locked position wherein the cylinder plug is rotationally locked relative to the housing and an unlocked position wherein the cylinder plug is rotational relative to the housing, wherein the at least one locking member includes a sidebar biased radially outward and received in a groove (225,227) along the lock housing In the locked position; a plurality of pin sets, each pin set including a keyway pin component and a locking pin component and positioned in the cylinder plug such that a portion of each keyway, pin component extends across the keyway, each keyway pin component selectively engageable with a respective locking pin component; a re-combinating member engaged with one of the components of each pin set and moveable between a first position wherein the keyway pin components are engaged with the locking pin components and a second position wherein the keyway pin components are disengaged from the locking pin components; and a reset actuator positioned within the cylinder plug with a portion aligned with the keyway, the reset actuator moveable between an engaged position wherein the re-combinating member position is locked relative to the cylinder plug and a non-engaged position wherein the re-combinating member position is moveable relative to the cylinder plug; characterized in that: each locking pin component includes a rotatable toothed gear defining a locking sidebar notch configured to receive the sidebar In the unlocked position. each locking pin component includes a rotatable toothed gear defining a locking sidebar notch configured to receive the sidebar In the unlocked position.