GM bulletin PIT6032B
What it saysThis Preliminary information communicates an issue with the front HVAC blower speed reducing to a lower speeding when it should be higher. NHTSA’s full summary ↓
GM filed this with NHTSA as a service bulletin dated Jun 26, 2023, received Jul 17, 2023, about the engine. It names 10 model years across Chevrolet and GMC (2022–2023). 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 · GMC.
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What the bulletin says
Source: NHTSA's summary of the manufacturer's communicationThis Preliminary information communicates an issue with the front HVAC blower speed reducing to a lower speeding when it should be higher. Engineering is working on a fix.
Document filed under this number
| Document | Kind | Dated | NHTSA id | At NHTSA |
|---|---|---|---|---|
| PIT6032B | Service bulletin | Jun 26, 2023 | 10239177 | not found |
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 6 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 10 model years this bulletin names have filed 3,696 complaints with NHTSA since 2015. 1,948 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 2022 GMC Sierra, the 54 owners who gave an odometer reading for Engine reported it at a median of 47,000 miles. That figure is one model year’s, not the whole range this bulletin covers — medians from different model years are not averaged.
i FEEL IT IS IN THE FUEL MANAGEMENT SYSTEM When driving along every now and then you can feel a vibration like diving on rumble strips. there is no rhyme or reason for it. I had it to the dealer and they told me that was normal, if you don't want it to do it then drive in 9th gear. I'm not going to shift to 9th every time I drive
2022 GMC Sierra · Engine · filed with NHTSA Jan 3, 2023 · ODI 11499958
In October 2024, the vehicle just shut off while we were driving down the road. Had to pull off to the side and got it going after about 5 minutes. Couldn't get the vehicle to replicate the problem so nothing chevy could do. No check engine light. No codes were given. On January 4th the vehicle started making a horrible noise.
2023 Chevrolet Suburban · Engine · filed with NHTSA Mar 11, 2025 · ODI 11647749
Vehicle continues to go into limp mode causing us to be stranded on the side of the road. It is related to DEF injection system issues. It sounds like this is a known issue with the software. We purchased the vehicle in August and have been unable to use the truck since purchasing as it continues to leave us stranded.
2023 Chevrolet Silverado · Engine · filed with NHTSA Jun 6, 2024 · ODI 11592815
In depth: 2023 Chevrolet Silverado engine problems → · 2022 Chevrolet Silverado engine problems → · 2023 Chevrolet Suburban engine problems → · 2022 Chevrolet Suburban 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 group169 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 |
|---|---|---|---|
| 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… |
| 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… |
| 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… |
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 PIT6032B 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 PIT6032B 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 PIT6032B cover?
The manufacturer filed it against 10 model years across 2 brands (Chevrolet and GMC): 2023 Chevrolet Silverado, 2022 Chevrolet Silverado, 2023 Chevrolet Suburban, 2022 Chevrolet Suburban, 2023 Chevrolet Tahoe, 2022 Chevrolet Tahoe and more. Whether one particular vehicle is affected is a matter of its VIN and its build, not its model year alone.