DTC B1B42-12: Front Left Inner Sensor - Circuit short to battery: Action

Refer to the appropriate system wiring diagrams and check the front bumper harness for damage. Check sensor circuit for short circuit to power. Repair or replace any wiring harness as required
Check the connector for integrity and damage, then re-connect sensor to confirm connection
Using the manufacturers approved diagnostic system clear the DTC and run the on demand self-test