GM bulletin 19-NA-237
What it saysThis service bulletin explains how to identify possible DEF system contamination. NHTSA’s full summary ↓
GM filed this with NHTSA as a service bulletin dated Aug 12, 2024, received Oct 11, 2022, about the engine — 4 documents under this number. It names 95 model years across Chevrolet, GMC and Cadillac (2016–2025). 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 · Cadillac.
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What the bulletin says
Source: NHTSA's summary of the manufacturer's communicationThis service bulletin explains how to identify possible DEF system contamination.
Documents filed under this number
| Document | Kind | Dated | NHTSA id | At NHTSA |
|---|---|---|---|---|
| 19-NA-237 | Service bulletin | Aug 12, 2024 | 11007718 | PDF, 364 KB |
| 19-NA-237 | Service bulletin | Apr 5, 2023 | 10235397 | PDF, 718 KB |
| 19-NA-237 | Service bulletin | Mar 16, 2023 | 10234105 | PDF, 718 KB |
| 19-NA-237 | Service bulletin | Sep 12, 2022 | 10222781 | PDF, 716 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 53 model years
and 11 more on this site: 2021 Chevrolet Silverado 3500HD, 2020 Chevrolet Silverado 3500HD, 2019 Chevrolet Silverado 3500HD, 2024 Chevrolet Suburban, 2023 Chevrolet Suburban, 2022 Chevrolet Suburban, 2021 Chevrolet Suburban, 2024 Chevrolet Tahoe, 2023 Chevrolet Tahoe, 2022 Chevrolet Tahoe, 2021 Chevrolet Tahoe.
Also filed against model years this site has no page for: 2019 Chevrolet 6500; 2018 Chevrolet G4500.
GMC 34 model years
and 26 more on this site: 2024 GMC Sierra, 2023 GMC Sierra, 2022 GMC Sierra, 2021 GMC Sierra, 2020 GMC Sierra, 2019 GMC Sierra, 2018 GMC Sierra, 2017 GMC Sierra, 2016 GMC Sierra, 2024 GMC Sierra 2500HD, 2023 GMC Sierra 2500HD, 2022 GMC Sierra 2500HD, 2021 GMC Sierra 2500HD, 2020 GMC Sierra 2500HD, 2019 GMC Sierra 2500HD, 2024 GMC Sierra 3500HD, 2023 GMC Sierra 3500HD, 2022 GMC Sierra 3500HD, 2021 GMC Sierra 3500HD, 2020 GMC Sierra 3500HD, 2019 GMC Sierra 3500HD, 2024 GMC Terrain, 2024 GMC Yukon, 2023 GMC Yukon, 2022 GMC Yukon, 2021 GMC Yukon.
Cadillac 8 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 93 model years this bulletin names have filed 18,816 complaints with NHTSA since 2015. 8,209 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 2019 Chevrolet Silverado, the 143 owners who gave an odometer reading for Engine reported it at a median of 71,000 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 · ODI 11627201
Engine hesitation, or misfiring. Jerking, or transmission shuttering when engine is at low RPM and on incline. (i.e. When traveling about 45mph and start up a hill, the rpm's are about 1300, and the transmission doesn't gear down, so it starts shuttering until you give it more acceleration than usual.) after dealing with this issue for…
2017 Chevrolet Silverado · Engine · filed with NHTSA Jul 18, 2018 · ODI 11112166
Multiple instances of diesel engine emissions system parts and software failure. While driving, towing or not, the DIC would randomly display a message that the DEF level is low and reduced speed will occur in x-amount of miles and that mileage would then begin a visible countdown on the DIC, sometimes much more quickly than the actual…
2021 GMC Sierra 3500HD · Engine · filed with NHTSA Nov 1, 2024 · ODI 11623109
In depth: 2024 Cadillac Escalade engine problems → · 2023 Cadillac Escalade engine problems → · 2022 Cadillac Escalade engine problems → · 2021 Cadillac Escalade 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 group270 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 |
|---|---|---|---|
| N262572131-01 | Service campaign | Oct 23, 2026 | Customer Satisfaction Program. Certain vehicles listed above may have a condition in which the oil galley in the cylinder head was not dril… |
| N262566800 | Service campaign | Oct 20, 2026 | Certain vehicles listed above may have a condition in which the incorrect transmission parts were used. Dealers will replace the transmissio… |
| 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… |
| N262572131 | Service campaign | Aug 28, 2026 | Customer Satisfaction Program. Certain vehicles listed above may have a condition in which the oil galley in the cylinder head was not dril… |
| 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… |
| N262546590-01 | Service campaign | Jul 15, 2026 | Certain vehicles listed above, may have a condition where coolant leaks from the radiator hose quick connect at the radiator inlet. This sp… |
| N262552620 | Service campaign | May 11, 2026 | Certain vehicles may have a condition that could cause the cylinder 2 glow plug to fail. If this failure occurs, the Malfunction Indicator… |
| 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… |
Quote the number at the service desk. It is what the dealer’s system is keyed on.
Every manufacturer communication NHTSA holds for Chevrolet, GMC and Cadillac, by the number printed on the letter.
Common questions
Source: NHTSA, 49 CFR 579.5Is GM 19-NA-237 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 19-NA-237 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 19-NA-237 cover?
The manufacturer filed it against 95 model years across 3 brands (Chevrolet, GMC and Cadillac): 2024 Cadillac Escalade, 2023 Cadillac Escalade, 2022 Cadillac Escalade, 2021 Cadillac Escalade, 2023 Cadillac XT4, 2022 Cadillac XT4 and more. Whether one particular vehicle is affected is a matter of its VIN and its build, not its model year alone.