David Lambert "The ECU controls paper motion in the printer by continuously monitoring the various paper sensors and coordinating the timing with the other print processes. For a detailed explanation of paper movement and the interaction of the photosensors and solenoid with the paper movement process, see “Printer paper-feed system” on page 67.
Motor
The motor is controlled by the ECU. The motor provides all of the printer paper movement.
Printer laser/scanner drive
***The ECU sends signals to the laser/scanner assembly to modulate the laser diode “on” and “off” and to drive the laser/scanner motor***"
So it could be the ECU. Use the SM [document|27289] for a deep dive