A wrench light has come on in my 2006 Honda Accord: what does it mean?

I believe it's a change oil light. Once oil is changed then there's a reset button. Check the owner's manual or go online and look up the 2006 Honda Owner's Manual.

Part of 'maintenance minder' system meant to remind you when and what recommended services are due by time or miles. Comes on when 'oil life' is at or below 15%.