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Federal filingsHome›Trouble codes› P04FB
Diagnostic trouble code

P04FB

6 owner reports and 421 manufacturer filings across 52 model years from Buick, Cadillac, Chevrolet, GMC.

Powertrain Generic OBD-II code 421 manufacturer filings 6 owner reports

Where P04FB shows up

Source: NHTSA manufacturer communications and complaints
Model yearFiled underBulletinsOwner reportsParts
2023 GMC AcadiaNot specified101
2021 GMC AcadiaNot specified101
2022 Buick EnvisionNot specified10—
2021 Buick EnvisionNot specified10—
2022 Cadillac CT4Not specified10—
2021 Cadillac CT4Not specified10—
2020 Cadillac CT4Not specified10—
2022 Cadillac CT5Not specified10—
2021 Cadillac CT5Not specified10—
2020 Cadillac CT5Not specified10—
2019 Cadillac CT6Not specified10—
2022 Cadillac XT4Not specified10—
2021 Cadillac XT4Not specified10—
2020 Cadillac XT4Not specified10—
2023 Cadillac XT5Not specified10—
2022 Cadillac XT5Not specified10—
2021 Cadillac XT5Not specified10—
2020 Cadillac XT5Not specified10—
2023 Chevrolet BlazerNot specified10—
2022 Chevrolet BlazerNot specified10—
2021 Chevrolet BlazerNot specified10—
2020 Chevrolet BlazerNot specified10—
2022 GMC AcadiaNot specified10—
2020 GMC AcadiaNot specified10—
2023 Buick EnvisionNot specified9—

Showing the 25 model years where P04FB appears most; it is on file for 52 in total.

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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P04FB by make

The same record, one make at a time: the model years, bulletins and owner reports that name P04FB on that maker’s vehicles.

Cadillac 32Chevrolet 8GMC 7Buick 5

What it gets filed under

Not specified 241 Engine 119 Power Train 16 Service Brakes 16 Back Over Prevention 9

What owners said

Source: NHTSA complaint database

Owners’ own words, one per nameplate, scrubbed of anything identifying. These are unverified reports filed with NHTSA — they are what was said, not a finding that it was true.

The engine code is P04FB and is commonly found as an issue when you do a search
2025 Chevrolet Equinox Apr 24, 2026 NHTSA owner report
The contact stated while driving at an undisclosed speed, the check engine warning light illuminated and DTC: P04FB; was displayed
2021 GMC Acadia at 37,000 miles Feb 9, 2026 NHTSA owner report

421 manufacturer filings name P04FB. 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.

Read the filingsSearch every bulletin →
Photo: Compagnons / Unsplash

Manufacturer filings that name it

Source: NHTSA manufacturer communications

Service bulletins and campaigns whose filed summary names P04FB.

What P04FB means

Source: SAE J2012 / OBD-II

P04FB 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.

From here
Get a model's new bulletins by email See what owners reported Look up a bulletin by its number Watch a VIN for new recalls

Common questions about P04FB

Source: NHTSA files and the OBD-II standard

Can I keep driving with P04FB 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.

Where to go next

pages beside this code
Filed alongside B3055 Another code that appears in the same filings and owner reports as P04FB.Filed alongside B3060 Another code that appears in the same filings and owner reports as P04FB.Vehicle 2023 GMC Acadia The model year P04FB is filed against most often.The data Trouble codes by API GET /v1/dtc joins every code to bulletins and owner reports — free tier, no card.