P203B on the 2016 Ford F-650
The bulletins listed name this code in NHTSA's summary, or are about the same components. A bulletin or a recall listed here may apply to the model year. None of it is a diagnosis.
Nobody has written a description of this code yet.
| TSB 23-2161 | 2023-05-31. Service bulletin. 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 22-2191 | 2022-05-24. Service bulletin. 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 21-2336 | 2021-10-05. Service bulletin. 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, 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. To correct the condition, follow the Service Procedure steps to replace the reductant tank harness, the reductant pump/heater assembly and/or the reductant tank. |
| TSB 21-2287 | 2021-09-04. Service bulletin. This article supersedes TSB 17-0068 to update the Service Procedure and Parts List. Some 2016-2017 F-650/F-750 vehicles equipped with a 6.7L diesel engine and built on or before 21-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 Reprogramming tool. |
| tsb17-0068 | 2017-12-14. Service bulletin. Some 2016-2017 F-650/750 vehicles equipped with a 6.7L engine and built on or before 21-Aug-2017 may exhibit an illuminated MIL with DTC P203B in the powertrain control module (PCM) memory. This may be due to a low voltage condition reducing the ability of the integrated reductant level sensor to monitor reductant tank fluid levels. Follow the Service Procedure steps to correct the condition. |
| SSM 46510 | 2017-08-01. Service bulletin. 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 tank. If the applicable pinpoint test in the powertrain control/emission diagnostic (PC/ED) or workshop manual (WSM) directs replacement of the integrated reductant level sensor, do not attempt any repairs at this time and release the vehicle. Engineering is currently investigating this concern, monitor OASIS for updates regarding latest information and diagnostic direction. |
6 on file from NHTSA, as of 2026-10-19. See them in the bulletin list. A bulletin lists model years: read the document for which vehicles it concerns.