The scanner motor (M5) [B] drives the drive belt [D] in order to move the scanner carriage [A] along the guide rod [C].

Scanning starts with the scanner carriage [A] from the scanner HP sensor (S12) [E]. After scanning, the scanner carriage returns to the scanner HP sensor (S12). The actuator for the scanner HP sensor (S12) is on the underside of the carriage.

If you want to move the carriage, DO NOT pull it directly, instead, use the drive belt.