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P204C 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.

Bulletins for this model year that name P204C
TSB 23-21612023-05-31. 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 22-21912022-05-24. 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 21-23362021-10-05. 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.

3 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.