P203B on Ford vehicles

A model year is listed because the code is named in its own record — a bulletin filed against it, or an owner’s complaint about it — not because every one of these vehicles sets it. Counts are documents in NHTSA’s files, not failure rates.

Owners’ own words, scrubbed of anything identifying. Unverified reports filed with NHTSA — what was said, not a finding that it was true.

Bulletins and campaigns Ford filed with NHTSA whose summary names P203B. Quote the document number at the service desk — it is a diagnosis the maker has already written down.

• SSM 48489 Service bulletin
  2020-01-27 · 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.
• TSB 20-2044 Service bulletin
  2020-02-14 · 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 PC
• TSB-20-2063 Service bulletin
  2020-03-05 · 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 condi
• SSM 46510 Service bulletin
  2017-04-05 · Fuel System, Diesel
• Some 2017 F-Super Duty and 2016-2017 F650/F750 vehicles equipped with 6.7L engine may exhibit an inaccurate diesel exhaust fluid (DEF) level indicator or warning message with or without an illuminated malfunction indicator lamp (MIL) and diagnostic trouble code (DTC) P203B. This concern may be due to intermittent loss of signal from the reductant level sensor that is integrated into the reductant
• TSB 20-2270 Service bulletin
  2020-08-18 · Engine And Engine Cooling
• Some 2017 F-Super Duty vehicles equipped with a 6.7L diesel engine built on or before 04-Aug-2017 may exhibit an illuminated malfunction indicator lamp (MIL) with diagnostic trouble code (DTC) P203B. This may be due to a low voltage condition during engine cranking. To correct this condition, reflash the diesel exhaust fluid (DEF) reductant level sensor/quality module using the Urea Sensor Reprogr
• TSB 21-2336 Service bulletin
  2021-09-28 · Electrical System
• Some 2018-2020 F-150 vehicles built on or before 1-Apr-2020 equipped with a 3.0L diesel engine, 2017-2019 F-Super Duty vehicles built on or before 30-Oct-2019 equipped with a 6.7L engine and 2016-2019 F-650/F-750 vehicles built on or before 30-Oct-2019 equipped with a 6.7L engine may exhibit an illuminated malfunction indicator lamp (MIL) with diagnostic trouble codes (DTCs) P21DD, P20BA. P20B9, P
• TSB 22-2191 Service bulletin
  2022-05-17 · 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 U0
• TSB 21-2055 Service bulletin
  2021-03-04 · 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 sto
• TSB 21-2248 Service bulletin
  2021-09-14 · Electrical System
• 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
• SSM 51891 Service bulletin
  2023-08-28 · Engine And Engine Cooling
• Some 2023 F-Super Duty vehicles equipped with a 6.7L engine may exhibit an illuminated malfunction indicator lamp (MIL) with diagnostic trouble codes (DTC) U02A2, P206B, P203B, P208A, P20FA, P20FD, and/or P20FC stored in the powertrain control module (PCM). Before performing normal diagnostics, inspect connectors C1273C (32 pin) and C406 (14 pin) for proper connection. Also disconnect and inspect
• SSM 52299 Service bulletin
  2024-02-27 · Power Train
• Some 2023-2024 F-Super Duty vehicles equipped with a 6.7L engine may exhibit an illuminated malfunction indicator lamp (MIL) with diagnostic trouble codes (DTC) U02A2, P206B, P203B, P208A, P20FA, P20FD, and/or P20FC stored in the powertrain control module (PCM). Before performing normal diagnostics, inspect connectors C1273C (32 pin) and C406 (14 pin) for proper connection. Also disconnect and ins
• TSB 24-2256 Service bulletin
  2024-08-22 · Power Train
• Some 2023-2024 F-Super Duty vehicles built on or before 22-Jul-2024 and equipped with a 6.7L engine may exhibit an illuminated malfunction indicator lamp (MIL) with diagnostic trouble codes (DTC) P203B, P206B, and/or P2201:92 stored in the powertrain control module (PCM). This may be due to the software in the PCM. To correct the condition, follow the Service Procedure to reprogram the PCM using t

A stored code names the test that failed, never the part that caused it. The record above is what Ford and its owners have filed about it; the code’s page across every make has the whole file.