Some 2021 F-150 vehicles equipped with blind spot information system (BLIS) and rear lamp assemblies utilizing 2 incandescent bulbs and built on 01-Jan-2021 and through 30-Apr-2021 may experience a turn signal indicator flashing fast in the instrument panel cluster (IPC) with one or more of the rear lamp bulbs not flashing. This may be due to an incandescent rear lamp bulb not being completely inserted or has fallen out of the bulb socket. To correct the condition, follow the Service Procedure to inspect and replace the rear lamp wire harness.
