Canon PIXMA MX310 series Quick Start Manual page 97

Cause
Document Jams in the ADF (Document
Output Slot).
If the document is jammed in the Document Output Slot, pull it out.
When rescanning the document after clearing the error, rescan it from the
first page.
If you cannot remove the document or the document tears inside the machine,
or if the document jam error continues after removing the document, contact
your Canon service representative.
Action
Troubleshooting 93