Technical Service Bulletin SSM 51648 — 2021 FORD F-550 SD

Some 2020-2022 F-Super Duty vehicles equipped with a 6.7L engine may experience a lack of power due to snow packing of the engine air cleaner when operating in extremely snowy conditions. This may also be due to ice forming in the air intake while operating in temperatures below -22°F (-30°C). Diagnostic trouble code (DTC) P1548 may be present in the powertrain control module (PCM). To supplement heavy snow environment pre-filter service kit (service part LC3Z-9K635-AA), a front grill cover (service part NC3Z-19A413-A) is now available for service but is not a warrantable item. It is recommended that the front grill cover be removed at temperatures greater than 10°F (-12°C) and reinstall in subsequent winter seasons in order to maintain optimal vehicle performance.