GM bulletin 22-NA-112
What it saysThis technical bulletin provides repair information to correct a customer concern of 2020 - 2022 Silverado and Sierra Equipped with Diesel Engine Setting DTCs P20BB or P20C3. NHTSA’s full summary ↓
GM filed this with NHTSA as a service bulletin dated Jan 19, 2024, received Jun 6, 2022, about the engine — 2 documents under this number. It names 18 model years across Chevrolet and GMC (2020–2022). 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 technical bulletin provides repair information to correct a customer concern of 2020 - 2022 Silverado and Sierra Equipped with Diesel Engine Setting DTCs P20BB or P20C3.
Trouble codes it names: P20BB P20C3
Documents filed under this number
| Document | Kind | Dated | NHTSA id | At NHTSA |
|---|---|---|---|---|
| 22-NA-112 | Service bulletin | Jan 19, 2024 | 10249713 | PDF, 128 KB |
| 22-NA-112 | Service bulletin | May 25, 2022 | 10213523 | PDF, 112 KB |
What the document itself lists
The manufacturer titles it “2020 - 2022 Silverado and Sierra Equipped with Diesel Engine Setting DTCs P20BB or”.
Part the bulletin names
| Part number | Description | Qty | Find it |
|---|---|---|---|
| 87836557 | — | — |
Labour operation and the time the manufacturer allows
| Operation | Description | Time |
|---|---|---|
| 2888718 | Reductant Control Module Reprogramming with SPS for DEF with DTCs P20BB or P20C | 0.3 hrs |
Read by machine from the document NHTSA serves (6 pages), read Sep 30, 2026. A part number is shown only where it matches GM’s own catalogue shape, an operation only with its code and time, and a description only where the reader got it whole; anything it could not settle is left out, and the PDF is the record. Times are the manufacturer’s warranty allowances, not a quote. Listings and prices on eBay Motors are the seller’s.
Affiliate disclosure: some links on this page are affiliate links. If you request a quote or buy through them we may earn a commission at no extra cost to you. Nothing on this page changes because of it.
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.
Find the diesel for the 2022 Silverado →Affiliate disclosure: some links on this page are affiliate links. If you request a quote or buy through them we may earn a commission at no extra cost to you. Nothing on this page changes because of it.
Model years it names
Source: as the manufacturer filed themChevrolet 9 model years
GMC 9 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 18 model years this bulletin names have filed 4,653 complaints with NHTSA since 2015. 2,769 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.
On the 2021 Chevrolet Silverado, the 108 owners who gave an odometer reading for Engine reported it at a median of 65,000 miles. That figure is one model year’s, not the whole range this bulletin covers — medians from different model years are not averaged.
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
Electrical components are failing in the tailgate lock/unlock mechanism. The tailgate goes up and down on its own while in park. It will also go up and down on its own after the truck is off and unattended This started happening about a week ago. It is available for inspection upon request and has not been inspected by any agency yet.
2021 Chevrolet Silverado 3500HD · Electrical System · filed with NHTSA Nov 27, 2024 · ODI 11627812
The contact owns a 2020 Chevrolet Silverado 3500. The contact stated that while driving on at 70-73 MPH, the vehicle unexpectedly downshifted to first gear. The contact slammed on the brake pedal and pulled over to the side of the road. The vehicle was turned off. The contact stated that the tachometer had increased to over 3,000 RPM.
2020 Chevrolet Silverado 3500HD · Engine · filed with NHTSA Feb 10, 2025 · ODI 11641761
In depth: 2022 Chevrolet Silverado engine problems → · 2022 Chevrolet Silverado electrical problems → · 2021 Chevrolet Silverado engine problems → · 2021 Chevrolet Silverado electrical 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 group189 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… |
| 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… |
| 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… |
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 22-NA-112 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 22-NA-112 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 22-NA-112 cover?
The manufacturer filed it against 18 model years across 2 brands (Chevrolet and GMC): 2022 Chevrolet Silverado, 2021 Chevrolet Silverado, 2020 Chevrolet Silverado, 2022 Chevrolet Silverado 2500HD, 2021 Chevrolet Silverado 2500HD, 2020 Chevrolet Silverado 2500HD and more. Whether one particular vehicle is affected is a matter of its VIN and its build, not its model year alone.