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Service bulletins for the 2021 Ford F-550

A bulletin is a manufacturer's communication to its dealers, as NHTSA indexes it. The summary is NHTSA's. The document is the manufacturer's: read it at NHTSA. A bulletin is not a recall, and listing a model year does not mean every vehicle of it is concerned.

237 on file from NHTSA, as of 2026-10-19.

About C0020 on the 2021 Ford F-550: what the code means, and the bulletins and recalls about the same components.

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Only bulletins with trouble code: C0020 are shown. Show all

Bulletins, newest first
TSB 23-21332023-05-04. Service bulletin. ELECTRICAL SYSTEM. Some 2020-2022 F-Super Duty vehicles may exhibit a condition where the engine will not turn off and/or have various electrical symptoms including a dead battery, horn stays on and no crank/no start. The vehicle may also have an illuminated anti-lock braking system (ABS) indicator with diagnostic trouble codes (DTCs) C0020 and U3003 in the ABS module. This may be a result of water/moisture intrusion into the battery junction box (BJB). The BJB is located under the hood of the vehicle. This water/moisture intrusion may be related to the BJB cover not installed completely or broken cover tabs/locking fingers allowing water/moisture into the BJB. To correct the condition, follow the Service Procedure to inspect for water/moisture intrusion into the BJB and replace the BJB and cover if water/moisture intrusion is found.
TSB 22-24432022-12-02. Service bulletin. UNKNOWN OR OTHER; EQUIPMENT:ELECTRICAL; ELECTRICAL SYSTEM. This article supersedes TSB 22-2313 to update the Parts List, Service Procedure, and vehicle production fix dates. Some 2020-2022 F-Super Duty vehicles may exhibit a condition where the engine will not turn off and/or have various electrical symptoms including a dead battery, horn stays on and no crank/no start. The vehicle may also have an illuminated anti-lock braking system (ABS) indicator with diagnostic trouble codes (DTCs) C0020 and U3003 in the ABS module. This may be a result of water/moisture intrusion into the battery junction box (BJB). The BJB is located under the hood of the vehicle. This water/moisture intrusion may be related to the BJB cover not installed completely or broken cover tabs/locking fingers allowing water/moisture into the BJB. To correct the condition, follow the Service Procedure to inspect for water/moisture intrusion into the BJB and replace the BJB and cover if water/moisture intrusion is found.
TSB 22-20442022-02-23. Service bulletin. ELECTRICAL SYSTEM. Some 2020-2022 F-Super Duty vehicles may exhibit a condition where the engine will not turn off and/or have various electrical symptoms including a dead battery, horn stays on and no crank/no start. The vehicle may also have an illuminated anti-lock braking system (ABS) indicator with diagnostic trouble codes (DTCs) C0020 and U3003 in the ABS module. The vehicle may not shift out of park (P) and/or have continuously illuminated brake lamps with DTCs P0504 and/or C0040. This may be a result of water/moisture intrusion into the battery junction box (BJB). The BJB is located under the hood of the vehicle. This water/moisture intrusion may be related to the BJB cover not installed completely or broken cover tabs/locking fingers allowing water/moisture into the BJB. To correct the condition, follow the Service Procedure steps to inspect for water/moisture intrusion into the BJB and replace the BJB if water/moisture intrusion is found.
TSB 22-20042022-02-04. Service bulletin. ELECTRICAL SYSTEM. Some 2020-2022 F-Super Duty vehicles may exhibit a condition where the engine will not turn off and/or have various electrical symptoms including a dead battery, horn stays on and no crank/no start. The vehicle may also have an illuminated anti-lock braking system (ABS) Indicator with DTCs C0020 and U3003 in the ABS module. This may be a result of water/moisture intrusion into the battery junction box (BJB). The BJB is located under the hood of the vehicle. This water/moisture intrusion may be related to the BJB cover not installed completely or broken cover tabs/locking fingers allowing water/moisture into the BJB. To correct the condition, follow the Service Procedure steps to inspect for water/moisture intrusion into the BJB and replace the BJB if water/moisture intrusion is found.
TSB 21-21762021-09-02. Service bulletin. ELECTRICAL SYSTEM. Some 2020-2021 F-Super Duty vehicles may exhibit a condition where the engine will not turn off and/or have various electrical symptoms including a dead battery, horn stays on and no crank/no start. The vehicle may also have an illuminated anti-lock braking system (ABS) Indicator with DTCs C0020 and U3003 in the ABS module. This may be a result of water/moisture intrusion into the battery junction box (BJB). The BJB is located under the hood of the vehicle. This water/moisture intrusion may be related to the BJB cover not installed completely or broken cover tabs/locking fingers allowing water/moisture into the BJB. To correct the condition, follow the Service Procedure steps to inspect for water/moisture intrusion into the BJB and replace the BJB if water/moisture intrusion is found.

The summaries are NHTSA's. Each bulletin's page links NHTSA's copy of the manufacturer's document.