GM bulletin PIP5940
What it saysThis Preliminary information communicates a change in service procedure for the thermostat on this enigne. NHTSA’s full summary ↓
GM filed this with NHTSA as a service bulletin dated Sep 22, 2023, received Dec 26, 2023, about the engine. It names 28 model years across Chevrolet, GMC, Buick and Cadillac (2017–2023). 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 · Buick · Cadillac.
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What the bulletin says
Source: NHTSA's summary of the manufacturer's communicationThis Preliminary information communicates a change in service procedure for the thermostat on this enigne.
Document filed under this number
| Document | Kind | Dated | NHTSA id | At NHTSA |
|---|---|---|---|---|
| PIP5940 | Service bulletin | Sep 22, 2023 | 10247776 | 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 4 model years
GMC 7 model years
Buick 6 model years
Cadillac 11 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 28 model years this bulletin names have filed 2,819 complaints with NHTSA since 2015. 502 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 2017 GMC Acadia, the 28 owners who gave an odometer reading for Engine reported it at a median of 41,000 miles. That figure is one model year’s, not the whole range this bulletin covers — medians from different model years are not averaged.
I was driving on express way 96W Left lane busy 5 o'clock traffic Car just died it was stop n go I could have been killed if it wasn't for a man that stopped behind me he couldn't help another person stopped and push the car in N To a grass area where at least I wouldn't be smashed in Called 911 state police inform help van He didn't…
2020 Chevrolet Blazer · Engine · filed with NHTSA Oct 25, 2023 · ODI 11551752
I noticed a water sloshing sound behind the dash when first starting out for about a month. I didn’t get any warning lights or notice anything leaking under the car but when I checked under the hood the coolant reservoir was empty. I made appointment at GM dealership and they found I had a leak along the side seam of my radiator.
2021 Cadillac XT6 · Engine · filed with NHTSA Oct 20, 2026 · ODI 11772504
The contact owns a 2020 Cadillac XT6. The contact stated while driving at 35 MPH, the vehicle lost power. The vehicle was restarted from the Cadillac App via phone. The contact stated that during the second failure " The steering assist is reduced drive with care" warning message and the check engine warning light illuminated.
2020 Cadillac XT6 · Engine · filed with NHTSA Dec 23, 2024 · ODI 11632207
In depth: 2020 Chevrolet Blazer engine problems → · 2019 GMC Acadia engine problems → · 2017 GMC Acadia 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 group99 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 |
|---|---|---|---|
| N262570770-03 | Service campaign | Oct 16, 2026 | Certain vehicles may have a condition in which the thermal break tabs induce stress into the radiator causing a coolant leak. Dealers are t… |
| N262570770-02 | Service campaign | Sep 25, 2026 | Certain vehicles may have a condition in which the thermal break tabs induce stress into the radiator causing a coolant leak. Dealers are to… |
| N262570770-01 | Service campaign | Sep 18, 2026 | Certain vehicles may have a condition in which the thermal break tabs induce stress into the radiator causing a coolant leak. Dealers are to… |
| N262570770 | Service campaign | Sep 15, 2026 | Certain vehicles may have a condition in which the thermal break tabs induce stress into the radiator causing a coolant leak. Dealers are to… |
| 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… |
| N252540910 | Service campaign | Feb 25, 2026 | Service Update. Certain vehicles listed above may have a condition in which a quality issue with the engine was identified. Dealers will re… |
| N252508350 | Service campaign | Oct 21, 2025 | Certain vehicles listed above, may have a condition that could cause the engine coolant thermostat to open at a lower temperature than inten… |
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, Buick and Cadillac, by the number printed on the letter.
Common questions
Source: NHTSA, 49 CFR 579.5Is GM PIP5940 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 PIP5940 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 PIP5940 cover?
The manufacturer filed it against 28 model years across 4 brands (Chevrolet, GMC, Buick and Cadillac): 2019 Buick LaCrosse, 2018 Buick LaCrosse, 2017 Buick LaCrosse, 2020 Buick Regal, 2019 Buick Regal, 2018 Buick Regal and more. Whether one particular vehicle is affected is a matter of its VIN and its build, not its model year alone.