B0021-12: Left Curtain Deployment Control 1 - Circuit short to battery: Action

NOTE: The airbag connector has a locking plunger (orange tab) which should only fully lock when the two connectors are securely mated, male to female. If the plunger can move to the locked position easily when not mated (ie: using reasonable pressure), then this indicates that the connector is damaged. Repair the wiring harness as necessary

Refer to the electrical circuit diagrams and check the left side air curtain circuit for short circuit to power