Canon MultiPASS C5000 Service Manual page 76

Power from the paper feed motor is switched separation and feed of the
for
paper, and nozzle cleaning mechanisms by the direction of paper feed motor
rotation, the slide lock pin on the purge unit and swing gear. When the
carriage moves in front of the purge unit, the carriage pushes the control pin,
and releases the swing gear driven by the paper feed motor. When the paper
feed motor rotates in the paper feed direction in this state, the swing gear
rotates and moves up to the auto sheet feeder drive gear to drive the auto sheet
feeder. Alternately, when the paper feed motor rotates in the reverse direction,
the swing gear rotates and moves up to the purge drive gear to drive the purge
unit.
When the control pin is locked, the paper feed roller is driven to feed the paper.