Ford Expedition 2018–2021 — technical service bulletin
Bulletin SSM 50347 · NHTSA communication 10205483 · issued Dec 14, 2021
Technical service bulletin
communication type
Exterior Lighting
component
2018–2021
model years
8
vehicle entries
Official summary
Some 2018 2021 Expedition/Navigator vehicles may exhibit inoperative reverse lamps with DTC B1277 stored in the body control module (BCM). The vehicle may also exhibit the auto dimming rear view mirror becoming dark as soon as the key is turned on or is inoperative. This may be due to incorrect wiring of an aftermarket 5 pin jumper connector from a non-Ford windshield supplier that is causing a short to ground. To correct this condition, inspect if the windshield was recently replaced and verify the circuits in the 5 pin jumper connector located between connector C9440 and C9224 are routed in
Vehicles covered
What a TSB means. Technical service bulletins are repair guidance manufacturers send to dealers — they are not recalls, and repairs are not automatically free (warranty extensions are an exception worth checking). The full document is available via NHTSA’s vehicle lookup.