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Service bulletins for the 2020 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.

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

About P203B on the 2020 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: P203B are shown. Show all

Bulletins, newest first
TSB 23-21612023-05-31. Service bulletin. ELECTRICAL SYSTEM. Some 2018-2021 F-150 vehicles equipped with a 3.0L diesel engine, 2016-2022 F-650/F-750 vehicles equipped with a 6.7L engine, and 2017-2022 F-Super Duty vehicles equipped with a 6.7L engine and built on or before 08-Mar-2022 may exhibit an illuminated malfunction indicator lamp (MIL) with diagnostic trouble codes (DTCs) P21DD, P20BA. P20B9, P204C, P208A, P208B, P208C, P203B, P205B, P21CD and/or U02A2 in the powertrain control module (PCM). This may be due to water intrusion within connectors C3613 and/or C4851/C3610 on the reductant harness going to the reductant pump/heater assembly and the reductant level sensor/quality module. This may also be due to movement of the wiring harness causing terminal fretting. To correct the condition, follow the Service Procedure to replace the reductant tank harness, the reductant pump/heater assembly and/or the reductant tank, as well as securing the wiring harness using a cable zip tie fastener.
TSB 22-21912022-05-24. Service bulletin. ELECTRICAL SYSTEM. Some 2018-2021 F-150 vehicles equipped with a 3.0L diesel engine, 2016-2022 F-650/F-750 vehicles equipped with a 6.7L engine, and 2017-2022 F-Super Duty vehicles equipped with a 6.7L engine and built on or before 08-Mar-2022 may exhibit an illuminated malfunction indicator lamp (MIL) with diagnostic trouble codes (DTCs) P21DD, P20BA. P20B9, P204C, P208A, P208B, P208C, P203B, P205B, P21CD and/or U02A2 in the powertrain control module (PCM). This may be due to water intrusion within connectors C3613 and/or C4851/C3610 on the reductant harness going to the reductant pump/heater assembly and the reductant level sensor/quality module. This may also be due to movement of the wiring harness causing terminal fretting. To correct the condition, follow the Service Procedure to replace the reductant tank harness, the reductant pump/heater assembly and/or the reductant tank, as well as securing the wiring harness using a cable zip tie fastener.
TSB 21-22482021-09-30. Service bulletin. ELECTRICAL SYSTEM; POWER TRAIN:AUTOMATIC TRANSMISSION:CONTROL MODULE (TCM/PCM/TECM). This article supersedes TSB 21-2055 to update the Title, Issue, Action, vehicles affected and production fix date. Some 2020-2021 F-Super Duty vehicles equipped with a 6.7L engine built on or before 10-Feb-2021 may exhibit an illuminated malfunction indicator lamp (MIL) with diagnostic trouble codes (DTCs) P0300-P0308, P0603, P203B, P208B, P208C, P20EE, P2201, P24C2, P27B4, and/or P27B5 stored in the powertrain control module (PCM). The vehicle may also exhibit a forced idle condition. This may be due to various strategies within the PCM software. To correct the condition, follow the Service Procedure to reprogram the PCM.
TSB 21-20552021-04-03. Service bulletin. POWER TRAIN. This article supersedes TSB 20-2336 to update the Title, Issue, Action, vehicles affected and production fix date. Some 2020-2021 F-Super Duty vehicles equipped with a 6.7L engine built on or before 10-Feb-2021 may exhibit an illuminated malfunction indicator lamp (MIL) with diagnostic trouble codes (DTCs) P0300-P0308, P054F, P0603, P203B, P208B, P208C, P20EE, P2201, P24C2, P27B4, and/or P27B5 stored in the powertrain control module (PCM). The vehicle may also exhibit a forced idle condition. This may be due to various strategies within the PCM software. To correct the condition, follow the Service Procedure to reprogram the PCM.
TSB 20-23362020-10-02. Service bulletin. POWER TRAIN:AUTOMATIC TRANSMISSION:CONTROL MODULE (TCM/PCM/TECM); ELECTRICAL SYSTEM:SOFTWARE; ENGINE AND ENGINE COOLING. Some 2020 F-Super Duty vehicles equipped with a 6.7L engine built on or before 19-Aug-2020 may exhibit an illuminated malfunction indicator lamp (MIL) with diagnostic trouble codes (DTC) P0300-P0308, P0603, P203B, P208B, P208C, P2201, P24C2, P27B4, P07F6 and/or P27B5 stored in the powertrain control module (PCM). The vehicle may also exhibit a forced idle condition. This may be due to various strategies within the PCM software. To correct the condition, follow the Service Procedure to reprogram the PCM.
TSB-20-20632020-04-02. Service bulletin. ELECTRICAL SYSTEM. Some 2020 F-Super Duty vehicles equipped with a 6.7L engine built on or before 5-Feb-2020 may exhibit an illuminated malfunction indicator lamp (MIL) with diagnostic trouble codes (DTC) P203B, P2201 and/or DTC P27B4 stored in the powertrain control module (PCM). The vehicle may also exhibit a forced idle condition. This may be due to various strategies within the PCM software. To correct the condition, follow the Service Procedure to reprogram the PCM.
TSB 20-20442020-03-03. Service bulletin. POWER TRAIN:AUTOMATIC TRANSMISSION:CONTROL MODULE (TCM/PCM/TECM); ELECTRICAL SYSTEM. Some 2020 F-Super Duty vehicles equipped with a 6.7L engine built on or before 5-Feb-2020 may exhibit an illuminated malfunction indicator lamp (MIL) with diagnostic trouble codes (DTC) P203B, P2201 and/or DTC P274B stored in the powertrain control module (PCM). This may be due to various strategies within the PCM software. To correct the condition, follow the Service Procedure to reprogram the PCM.
SSM 484892020-02-04. Service bulletin. ELECTRICAL SYSTEM; ENGINE AND ENGINE COOLING. Some 2020 F-Super Duty vehicles equipped with 6.7L engine may exhibit an illuminated malfunction indicator lamp (MIL) and diagnostic trouble code (DTC) P203B. If performing pinpoint test RJ in the Powertrain Control and Emission Diagnosis (PC/ED) does not identify an issue, do not attempt any repairs at this time. Engineering is currently investigating. Monitor OASIS for updates.

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