Repair lock cylinders frozen 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. Hold the shutter door open with a paper clip or similar item.
3. Force air into the cylinder.

Use compressed air and a blow gun attachment.

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.