GM bulletin A222379711
What it saysGeneral Motors has decided to conduct a Voluntary Emission Recall involving certain vehicles. NHTSA’s full summary ↓
GM filed this with NHTSA as a service bulletin dated Mar 14, 2024, about the engine. It names 7 model years across Chevrolet and Buick (2020–2023). A service bulletin is not a safety recall: it is the manufacturer telling its dealers how to diagnose or repair a condition, and whether the work is paid for depends on the warranty in force. Quoting the number at a service desk can save a diagnosis.
One page for every brand it was filed under. Each brand’s bulletins: Chevrolet · Buick.
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What the bulletin says
Source: NHTSA's summary of the manufacturer's communicationPicked out of NHTSA’s summary below, word for word. The document itself is the record, and the dealer checks the VIN.
Emission Recall. General Motors has decided to conduct a Voluntary Emission Recall involving certain vehicles. The Engine Control Module (ECM) may not clear the permanent status of DTC P0521 (Engine Oil Pressure Sensor Performance). If the ECM had previously set a DTC P0521 and the permanent status is not properly cleared, the vehicle may not pass certain Emissions Inspection/Maintenance (I/M) tests. Dealers are to reprogram the ECM.
Trouble codes it names: P0521
Document filed under this number
| Document | Kind | Dated | NHTSA id | At NHTSA |
|---|---|---|---|---|
| A222379711 | Service bulletin | Mar 14, 2024 | 10251615 | PDF, 429 KB |
The summary is NHTSA’s abstract of the document, as filed under 49 CFR 579.5. One communication is usually filed as several documents — the bulletin, a dealer notice, an owner letter — and the number on any of them finds this page. A PDF link is shown only once NHTSA’s own server has been seen to serve that document; the rest are checked over the following nights. Quote the number at a service desk; it is what the dealer’s system is keyed on.
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Model years it names
Source: as the manufacturer filed themChevrolet 3 model years
Buick 4 model years
A vehicle page’s bulletin list shows the newest few communications filed against that model year; the count there is every one.
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What owners reported
Source: NHTSA complaint databaseOwners of the 7 model years this bulletin names have filed 589 complaints with NHTSA since 2015. 262 of them name Engine, Electrical System — the same broad component group this bulletin is filed under. NHTSA groups complaints coarsely, so that means the same area of the vehicle, not necessarily the same fault.
I bought my car, new, on 10/1/ 2023. The middle of November i noticed the headlights randomly dimming. On 12/3/23 I to the dealership to have them looked at. I was told there was nothing wrong but make an appt. they had my car 3 times in less than 2 months. I repeatedly told them my headlights were dimming and or going off.
2023 Buick Encore · Electrical System · filed with NHTSA Apr 26, 2024
The contact owns a 2023 Chevrolet Trailblazer. The contact stated that while driving 65 MPH, the “Engine Power Reduced" message was displayed, and the vehicle was unable to accelerate above 30 MPH. No warning lights were illuminated. The vehicle returned to normal functionality, but the failure became a regular occurrence.
2023 Chevrolet Trailblazer · Engine · filed with NHTSA Sep 19, 2024
The contact owns a 2021 Chevrolet Trailblazer. The contact stated that while driving at various speeds, the vehicle made an abnormal popping sound before the power steering and brakes failed. Additionally, the brake pedal became extremely sensitive while gently being depressed causing the vehicle to abruptly stop.
2021 Chevrolet Trailblazer · Electrical System · filed with NHTSA Nov 18, 2021
A complaint is one owner’s account, not a defect finding, and a bulletin is not a recall. Nothing here says this bulletin was issued because of these complaints, or that the repair it describes fixed them. Complaint files on this site begin in 2015.
More bulletins about the engine
Source: same model, same component group70 other manufacturer communications filed against these GM models under the same component group (engine), newest first. The eight newest are listed; the rest are on the Chevrolet list.
| Number | Kind | Dated | NHTSA’s summary |
|---|---|---|---|
| N242484750-02 | Warranty extension | Sep 1, 2026 | Special Coverage. Certain 2022 model year Buick Encore GX and Chevrolet Trailblazer vehicles, equipped with a 1.2L engine, may have a condi… |
| N242450640-02 | Warranty extension | Sep 1, 2026 | Special Coverage. Certain 2021 model year Buick Encore GX and Chevrolet Trailblazer vehicles, equipped with a 1.2L engine, may have a condi… |
| N232407740-03 | Warranty extension | Sep 1, 2026 | Special Coverage. Certain 2020 model year Buick Encore GX vehicles, equipped with a 1.2L engine, may have a condition that could cause the… |
| N242484750-01 | Warranty extension | Oct 20, 2025 | Special Coverage. Certain 2022 model year Buick Encore GX and Chevrolet Trailblazer vehicles, equipped with a 1.2L engine, may have a condi… |
| N242450640-01 | Warranty extension | Oct 20, 2025 | Special Coverage. Certain 2021 model year Buick Encore GX and Chevrolet Trailblazer vehicles, equipped with a 1.2L engine, may have a condi… |
| N232407740-02 | Warranty extension | Oct 20, 2025 | Special Coverage. Certain 2020 model year Buick Encore GX vehicles, equipped with a 1.2L engine, may have a condition that could cause the… |
| PIE0831A | Service bulletin | Jun 5, 2025 | This engineering information (EI) closure ends the need for gathering further information from technicians in regard to the Malfunction Indi… |
| 00-06-01-026R | Service bulletin | Jun 5, 2025 | This service bulletin provides information on replacing the intake manifold when the engine is replaced after severe internal engine damage. |
Quote the number at the service desk. It is what the dealer’s system is keyed on.
Every manufacturer communication NHTSA holds for Chevrolet and Buick, by the number printed on the letter.
Common questions
Source: NHTSA, 49 CFR 579.5Is GM A222379711 a recall?
No. A service bulletin is a manufacturer communication filed with NHTSA under 49 CFR 579.5; a safety recall carries an NHTSA campaign number (two digits, a letter, six digits) and a federal duty to repair for free. Check the vehicle’s recalls by VIN at nhtsa.gov/recalls, or on its page here.
Is the A222379711 repair free?
Not automatically. A service bulletin describes how to diagnose or repair a condition; who pays depends on the warranty in force, any extension, and the dealer. Quoting the number can save a diagnosis either way.
Which vehicles does A222379711 cover?
The manufacturer filed it against 7 model years across 2 brands (Chevrolet and Buick): 2023 Buick Encore, 2022 Buick Encore, 2021 Buick Encore, 2020 Buick Encore, 2023 Chevrolet Trailblazer, 2022 Chevrolet Trailblazer and more. Whether one particular vehicle is affected is a matter of its VIN and its build, not its model year alone.