Upvote:1
TIMATIC thinks your Canadian passport cannot admit you because it's expired. "Passports and other documents accepted for entry issued to nationals of Canada must be valid on arrival." Whether you would actually be turned away is another matter, but a cautious airline would be unwise to board you in violation of the clear instruction there.
However, TIMATIC goes on to say under the 'Passport exemptions' category, that you should be admitted with your Green Card: "Permanent residents of USA holding Permanent Resident/Resident Alien Card (Form I-551), arriving from USA or St. Pierre and Miquelon."
Therefore in my view you are in principle entitled to travel and enter Canada merely with your Green Card (although certainly bring along the Canadian passport as well). If you face trouble, ask for the agent in question to confirm the information in TIMATIC, under the passport exemptions category.
Information as of 10JUL15 / 1416 UTC
National Canada (CA) /Residence USA (US)
Embarkation USA (US) /Destination Canada (CA)
Canada (CA)
Passport required.
- Passports and other documents accepted for entry issued to
nationals of Canada must be valid on arrival.
- Warning: if departing from the USA (regardless of any
destination passport exemptions), a valid passport and/or
is required by the
US immigration authorities.
Passport Exemptions:
- Holders of a valid on arrival NEXUS Card issued to nationals
of Canada, if residing in USA.
- Permanent residents of USA holding Permanent
Resident/Resident Alien Card (Form I-551), arriving from USA
or St. Pierre and Miquelon.
VISA NOT REQUIRED.
Minors:
- If a travel document issued by Canada to minors under 16
years of age displays "Signature Not Required/non requise"
- Parent(s) traveling with a child under 18 years are strongly
Canada (CA)
Vaccinations not required.
Warning:
- Any visitor irrespective of length of intended stay in
Canada may be referred for medical examination if deemed
necessary.