Repair frozen lock cylinders due to cold weather using the following procedure:

Important: Be careful not to damage painted surfaces while using a heat gun.

1. Apply heat to the cylinder area with a heat gun.
2. Use a paper clip or similar item in order to hold the shutter door open.
3. Use compressed air and a blow gun attachment in order to force air into the cylinder.
4. While holding the shutter door open, inject a small amount of multi-purpose lubricant GM P/N 12346241 or equivalent.
5. Work the key into the cylinder several times.
6. Wipe any excess lubrication residue from the key.