P20FF
0 owner reports and 24 manufacturer filings across 5 model years from Chevrolet, GMC.
Where P20FF shows up
Source: NHTSA manufacturer communications and complaints| Model year | Filed under | Bulletins | Owner reports | Parts |
|---|---|---|---|---|
| 2020 GMC Sierra 2500HD | Power Train | 7 | — | |
| 2020 Chevrolet Silverado | Electrical System | 5 | — | Battery → |
| 2020 Chevrolet Silverado 2500HD | Electrical System | 5 | — | Battery → |
| 2020 GMC Sierra 3500HD | Engine | 4 | — | |
| 2020 Chevrolet Silverado 3500HD | Engine | 3 | — |
A model year appears here because the code is named in its record, not because every one of these vehicles sets it. Counts are mentions in the federal files, not failure rates — nobody publishes the denominator.
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What it gets filed under

24 manufacturer filings name P20FF. Start with what the maker wrote down.
A code names the test that failed, not the part. A bulletin that names it is often a diagnosis someone has already written down — quote its number at the service desk.
Manufacturer filings that name it
Source: NHTSA manufacturer communicationsService bulletins and campaigns whose filed summary names P20FF.
- 21-NA-214 Service bulletin2023-08-10 · Electrical System
- This technical bulletin provides repair information to correct a customer concern of Service Engine Soon Lamp being illuminated. They may also comment on multiple transmission issues including harsh or delayed shifts, slip, surge, shudder, noise, whine, growl, shake and/or vibration. As well as the exhaust brake not working or that they do not feel it. Technicians may find DTCs P2002, P2463, P2459
- 21-NA-214 Service bulletin2022-04-01 · Power Train
- This technical bulletin provides repair information to correct a customer concern of Service Engine Soon Lamp being illuminated with DTCs P2002, P2463, P2459, P144E, P0421, P0422, P0106 P20EE, P129F, P16F3, P20FF, P226D, P249D, P249E, P11CC and / or P11D5. They may also comment on multiple transmission issues including harsh or delayed shifts, slip, surge, shudder, noise, whine, growl, shake and/o
- N192266750-02 Service bulletin2020-02-14 · Fuel System, Diesel
- Service Update - On vehicles that are equipped with a 6.6L diesel engine, may have one or more of the following conditions exist: 1. The instrument panel cluster may incorrectly display the message ?DEF Low? when a diesel exhaust fluid (DEF) controller internal fault is detected (DTC P20FF), instead of displaying the proper ?Service DEF System? message. 2. The customer may complain of excessive e
- N192266750-01 Service bulletin2019-12-02 · Electrical System — Instrument Cluster/Panel
- N192266750-01 - Service Update (Revised Warranty Information and Service Procedure). On certain vehicles that are equipped with a 6.6L diesel engine, may have one or more of the following conditions exist: 1.The instrument panel cluster may incorrectly display the message ?DEF Low? when a diesel engine fluid (DEF) controller internal fault is detected (DTC P20FF), instead of displaying the proper
- N192266751 Service bulletin2019-10-08 · Engine And Engine Cooling
- N192266751 - Service Update (9 VINs moved from N192266750 due to different procedure). On certain vehicles that are equipped with a 6.6L diesel engine, may have one or more of the following conditions exist: 1.The instrument panel cluster may incorrectly display the message ?DEF Low? when a diesel engine fluid (DEF) controller internal fault is detected (DTC P20FF), instead of displaying the prop
- N192266750 Service bulletin2019-10-01 · Engine And Engine Cooling
- N192266750 - Service Update. On certain vehicles that are equipped with a 6.6L diesel engine, may have one or more of the following conditions exist: 1.The instrument panel cluster may incorrectly display the message ?DEF Low? when a diesel engine fluid (DEF) controller internal fault is detected (DTC P20FF), instead of displaying the proper ?Service DEF System? message. 2.The customer may compla
What P20FF means
Source: SAE J2012 / OBD-IIP20FF 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. It is the starting point of a diagnosis, not its conclusion — the same code has several possible causes and the cheap one is not always right.
Common questions about P20FF
Source: NHTSA files and the OBD-II standardCan I keep driving with P20FF stored?
Nobody can answer that from the code alone, and a site that does is guessing. A steady light means a fault was logged and the car should be checked soon; a flashing light means a severe misfire — slow down and get it seen as soon as possible, because severe misfire can quickly damage the catalytic converter. The safe read of this page is the mileage and the components, not permission.
Does a code mean the car is recalled?
No. Recalls are filed by campaign and matched by VIN, and none of them are triggered by a scan tool. If you want to know whether an open recall applies to one specific vehicle, check the VIN at nhtsa.gov/recalls — that is the only source that settles it.
Why do the counts here differ from other sites?
Because these are not estimates. Every number on this page is a count of documents in NHTSA's own files: manufacturer communications that name the code in their filed summary, and owner complaints that name it in the narrative. We do not model, weight or extrapolate them.
Will clearing the code fix it?
Clearing turns the light off and erases the freeze-frame data a technician would have used to work out what happened. If the condition is still there the code returns, usually within a few drive cycles, and the diagnosis now starts from less information than before.