Some 2021-2023 F-150 vehicles equipped with BLIS may experience inoperative blind spot monitoring with a Blind Spot System Fault message in the instrument panel cluster. This may also be accompanied by diagnostic trouble codes (DTCs) B118C:11 and/or B118C:15 stored in the driver door module (DDM), and/or B118D:11 and/or B118D:15 stored in the passenger door module (PDM). This may be due to the connector going from the mirror to the BLIS module (C576 for driver side, C676 for passenger side) having a pin out condition. To correct this condition, inspect the connector on the side experiencing the issue for a pin out condition and repair the circuit as necessary. Refer to Wiring Diagram, Cell 005, Connector Repair Procedures. If there is no issue with the connector or circuit, continue with normal diagnostics.
