P21DD on Ford vehicles
P21DD is named on 9 Ford model years (2017–2019): 36 manufacturer filings and 0 owner reports in NHTSA’s files, across F-250 Super Duty, F-350 Super Duty, F-450 Super Duty.
Which Ford model years name P21DD
Source: NHTSA manufacturer communications and complaints| Model year | Filed under | Bulletins | Owner reports |
|---|---|---|---|
| 2019 Ford F-250 Super Duty | Power Train | 4 | — |
| 2019 Ford F-350 Super Duty | Power Train | 4 | — |
| 2019 Ford F-450 Super Duty | Electrical System | 4 | — |
| 2018 Ford F-250 Super Duty | Power Train | 4 | — |
| 2018 Ford F-350 Super Duty | Power Train | 4 | — |
| 2018 Ford F-450 Super Duty | Engine | 4 | — |
| 2017 Ford F-250 Super Duty | Electrical System | 4 | — |
| 2017 Ford F-350 Super Duty | Electrical System | 4 | — |
| 2017 Ford F-450 Super Duty | Electrical System | 4 | — |
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.
Ford filings that name P21DD
Source: NHTSA manufacturer communicationsBulletins and campaigns Ford filed with NHTSA whose summary names P21DD. Quote the document number at the service desk — it is a diagnosis the maker has already written down.
- TSB 19-2315 Service bulletin2019-10-21 · Power Train
- Some 2017-2019 F-Super Duty vehicles built on or before 1-Aug-2018 equipped with a 6.7L engine may exhibit an illuminated malfunction indicator lamp (MIL) with diagnostic trouble codes (DTCs) P21DD, P204C, P21CD and/or U02A2 in the powertrain control module (PCM). This may be due to water intrusion within connectors C3613 and/or C4851 on the reductant harness going to the reductant pump/heater ass
- TSB 21-2336 Service bulletin2021-09-28 · Power Train — Automatic Transmission — Control Module (Tcm/Pcm/Tecm)
- 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 bulletin2022-05-17 · 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
What P21DD means
Source: SAE J2012 / OBD-IIP21DD sits in the generic range of the OBD-II standard, so it means the same thing on every vehicle sold in the United States — but WhichTrim does not carry a definition for it and will not invent one. What is on this page is the record: who named it and on what.
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.
Common questions
Source: NHTSA files and the OBD-II standardIs P21DD a known problem on Ford vehicles?
It is a documented one: NHTSA's files hold 36 manufacturer filings and 0 owner reports naming P21DD on 9 Ford model years (2017–2019). Whether it is a problem on one particular car is a diagnosis, not a count — but a bulletin that names the code on your model year is the place to start.
Which Ford models does P21DD appear on most?
2019 F-250 Super Duty (4 documents), 2018 F-250 Super Duty (4 documents), 2017 F-250 Super Duty (4 documents).
Does P21DD on a Ford mean it is recalled?
No. Recalls are filed by campaign and matched by VIN; no recall is triggered by a scan tool. Check the VIN at nhtsa.gov/recalls, or open the model year's page here for the campaigns filed against it.