GMC bulletin N232427120
What it saysCertain vehicles, equipped with the SLT package option 1 (RPO 4SA) AND exhaust system â performance (RPO NPP), may have a condition in which the customers were double charged for the performance exhaust system. NHTSA’s full summary ↓
GMC filed this with NHTSA as a service bulletin dated Dec 13, 2023, about the engine. It names 1 model year (2024). 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.
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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.
Customer Satisfaction Program - Certain vehicles, equipped with the SLT package option 1 (RPO 4SA) AND exhaust system â performance (RPO NPP), may have a condition in which the customers were double charged for the performance exhaust system. Dealers will provide the customer with a reimbursement check in the amount of $395.00 USD.
Document filed under this number
| Document | Kind | Dated | NHTSA id | At NHTSA |
|---|---|---|---|---|
| N232427120 | Service bulletin | Dec 13, 2023 | 10247182 | PDF, 151 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.
Doing the repair yourself, or pricing it before the shop does? Search the part by fitment on eBay Motors — the listing and the price are the seller’s.
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Model years it names
Source: as the manufacturer filed themA 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 1 model year this bulletin names have filed 386 complaints with NHTSA since 2015. 223 of them name Engine — 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 2024 GMC Sierra, the 27 owners who gave an odometer reading for Engine reported it at a median of 25,000 miles. That figure is one model year’s, not the whole range this bulletin covers — medians from different model years are not averaged.
Exactly what was described in the N192220080 Recall on New Model 2019 Chevy Silverados in cold climates (Like Utah winters) so at 45,280 miles the oil line popped out just like the recall described There were no oil leaks or signs of oil loss in the driveway where the truck is parked.
2024 GMC Sierra · Engine · filed with NHTSA Oct 31, 2024 · ODI 11622908
In depth: 2024 GMC Sierra engine problems →
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 group148 other manufacturer communications filed against the GMC Sierra under the same component group (engine), newest first. The eight newest are listed; the rest are on the GMC list.
| Number | Kind | Dated | NHTSA’s summary |
|---|---|---|---|
| N262576260 | Service campaign | Oct 15, 2026 | General Motors has decided to conduct a Voluntary Emission Recall. Certain vehicles may have a condition that could cause a small exhaust le… |
| N262568830 | Service campaign | Aug 4, 2026 | Certain vehicles listed above may have a condition in which the oil filter was not adequately tightened. Dealers are to check and tighten th… |
| N262548050 | Service campaign | Apr 24, 2026 | Certain vehicles, may have a condition that could cause the Catalytic Converter to fail. If this failure occurs, the Malfunction Indicator L… |
| N252494003-02 | Service campaign | Jan 21, 2026 | Certain vehicles listed above, may have a condition where the connecting rod and/or crankshaft engine components in these vehicles may have… |
| 25-NA-339 | Service bulletin | Nov 6, 2025 | Under Field Actions N252494000, N252494001, the service procedure includes performing a PICO test on vehicle engines within the identified s… |
| N252508341 | Service campaign | Sep 16, 2025 | Certain vehicles listed above, may have a condition that could cause the engine coolant control valve to fail an onboard vehicle diagnostic… |
| N252508340 | Service campaign | Sep 16, 2025 | Certain vehicles may have a condition that could cause the engine coolant control valve to fail. If this condition were to occur, the Malfun… |
| 24-NA-241 | Service bulletin | Sep 6, 2025 | This informational bulletin advises the technician of a part number change for long block engines used in the trucks noted. |

Quote the number at the service desk. It is what the dealer’s system is keyed on.
Every manufacturer communication NHTSA holds for GMC, by the number printed on the letter.
Common questions
Source: NHTSA, 49 CFR 579.5Is GMC N232427120 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 N232427120 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. Every GM warranty extension on file lists the ones GM has filed.
Which vehicles does N232427120 cover?
The manufacturer filed it against 1 model year: 2024 GMC Sierra. Whether one particular vehicle is affected is a matter of its VIN and its build, not its model year alone.