GM bulletin 25-NA-066
What it saysThis bulletin provides information on checking the inspection/maintenance system status parameters in the ECM and how to have the parameters reset so the system will run and pass. NHTSA’s full summary ↓
GM filed this with NHTSA as a service bulletin dated Mar 22, 2025, received Apr 24, 2025, about the fuel/propulsion system. It names 11 model years across Chevrolet and GMC (2023–2025). 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 · GMC.
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What the bulletin says
Source: NHTSA's summary of the manufacturer's communicationThis bulletin provides information on checking the inspection/maintenance system status parameters in the ECM and how to have the parameters reset so the system will run and pass.
Trouble codes it names: P0234 P0401 P0402 P0421 P0422 P2002 P20EE P22A7 P22F9 P22FB P22FE P2459 P24A0 P24A1 P24AF P24C7 P24D1 P24DA all 18 read from the document itself; NHTSA’s summary names none
Document filed under this number
| Document | Kind | Dated | NHTSA id | At NHTSA |
|---|---|---|---|---|
| 25-NA-066 | Service bulletin | Mar 22, 2025 | 11017176 | PDF, 141 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.
Model years it names
Source: as the manufacturer filed themChevrolet 7 model years
GMC 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 11 model years this bulletin names have filed 1,271 complaints with NHTSA since 2015. 544 of them name Engine, Fuel/Propulsion 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.
On the 2023 Chevrolet Silverado, the 30 owners who gave an odometer reading for Engine reported it at a median of 40,000 miles. That figure is one model year’s, not the whole range this bulletin covers — medians from different model years are not averaged.
The contact owned a 2024 GMC Sierra 2500 HD. The contact stated that after parking the vehicle at night and plugging in the engine block heater to a standard 110-Volt outlet with an extension cord; 15-minutes later neighbors were screaming to the contact to exit the residence because the vehicle had caught on fire, and the residence was…
2024 GMC Sierra 2500HD · Engine · filed with NHTSA Nov 25, 2024
The contact owns a 2024 Chevrolet Silverado 2500. The contact stated that while starting the vehicle, the check engine warning light illuminated. The vehicle was taken to the dealer, where the battery was disconnected temporarily to reset the ECM. The check engine warning light was reset; however, the failure reoccurred while driving.
2024 Chevrolet Silverado 2500HD · Engine · filed with NHTSA Nov 29, 2023
Component / System Failure The exhaust system, specifically the exhaust manifolds and previously the EGR system components, appear to have failed or malfunctioned, allowing exhaust gases to enter the passenger cabin. The dealer initially replaced the EGR cooler diverter on December 23, 2025. However, the condition persisted.
2025 GMC Sierra 2500HD · Engine · filed with NHTSA Feb 13, 2026
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 fuel/propulsion system
Source: same model, same component group62 other manufacturer communications filed against these GM models under the same component group (fuel/propulsion system), newest first. The eight newest are listed; the rest are on the Chevrolet list.
| Number | Kind | Dated | NHTSA’s summary |
|---|---|---|---|
| N262558690-02 | Service campaign | Sep 23, 2026 | General Motors has decided to conduct a Voluntary Emission Recall. Certain vehicles may have a condition which can cause the fuel pump power… |
| N262558690 | Service campaign | Sep 16, 2026 | General Motors has decided to conduct a Voluntary Emission Recall. Certain vehicles may have a condition which can cause the fuel pump power… |
| N242452131-02 | Emissions | Sep 11, 2026 | Emission Recall. General Motors has decided to conduct a Voluntary Emission Recall involving certain 2023-2024 model year Chevrolet Colorad… |
| N262558690-01 | Service campaign | Sep 1, 2026 | Emission Recall. General Motors has decided to conduct a Voluntary Emission Recall. Certain vehicles listed above may have a condition whic… |
| N242452130-01 | Service campaign | Aug 4, 2026 | Certain vehicles may have a condition in which the Engine Control Module (ECM) does not sufficiently control fuel injector flow rate under c… |
| N242438500-04 | Emissions | Nov 24, 2025 | Emission Recall. General Motors has decided to conduct a Voluntary Emission Recall involving certain 2024 Model Year Chevrolet Silverado an… |
| N252526150 | Service campaign | Nov 4, 2025 | Service Update. Certain vehicles listed above may have a condition which can cause the fuel pump power control module to fail. If this wer… |
| 24-NA-139 | Service bulletin | Apr 12, 2025 | This bulletin provides a procedure to replace the FPDCM if found to cause customers concerns of Crank No Start, Stalling, Loss of Power, Fue… |
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 GMC, by the number printed on the letter.
Common questions
Source: NHTSA, 49 CFR 579.5Is GM 25-NA-066 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 25-NA-066 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 25-NA-066 cover?
The manufacturer filed it against 11 model years across 2 brands (Chevrolet and GMC): 2025 Chevrolet Silverado, 2024 Chevrolet Silverado, 2023 Chevrolet Silverado, 2025 Chevrolet Silverado 2500HD, 2024 Chevrolet Silverado 2500HD, 2025 Chevrolet Silverado 3500HD and more. Whether one particular vehicle is affected is a matter of its VIN and its build, not its model year alone.