GM bulletin PI1394B
What it saysThis PI bulletin advises the technician on the proper way to install the pistons in an engine. NHTSA’s full summary ↓
GM filed this with NHTSA as a service bulletin dated Jan 12, 2024, received Feb 2, 2024, about the engine. It names 407 model years across Chevrolet, GMC, Buick and Cadillac (2016–2024). 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.
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 PI bulletin advises the technician on the proper way to install the pistons in an engine.
Document filed under this number
| Document | Kind | Dated | NHTSA id | At NHTSA |
|---|---|---|---|---|
| PI1394B | Service bulletin | Jan 12, 2024 | 10249579 | PDF, 93 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 224 model years
and 115 more on this site: 2023 Chevrolet Equinox, 2022 Chevrolet Equinox, 2021 Chevrolet Equinox, 2020 Chevrolet Equinox, 2019 Chevrolet Equinox, 2018 Chevrolet Equinox, 2017 Chevrolet Equinox, 2016 Chevrolet Equinox, 2024 Chevrolet Express, 2023 Chevrolet Express, 2022 Chevrolet Express, 2021 Chevrolet Express, 2020 Chevrolet Express, 2019 Chevrolet Express, 2018 Chevrolet Express, 2017 Chevrolet Express, 2016 Chevrolet Express, 2020 Chevrolet Impala, 2019 Chevrolet Impala, 2018 Chevrolet Impala, 2017 Chevrolet Impala, 2016 Chevrolet Impala, 2024 Chevrolet Malibu, 2023 Chevrolet Malibu, 2022 Chevrolet Malibu, 2021 Chevrolet Malibu, 2020 Chevrolet Malibu, 2019 Chevrolet Malibu, 2018 Chevrolet Malibu, 2017 Chevrolet Malibu, 2016 Chevrolet Malibu, 2017 Chevrolet SS, 2016 Chevrolet SS, 2024 Chevrolet Silverado, 2023 Chevrolet Silverado, 2022 Chevrolet Silverado, 2021 Chevrolet Silverado, 2020 Chevrolet Silverado, 2019 Chevrolet Silverado, 2018 Chevrolet Silverado, 2017 Chevrolet Silverado, 2016 Chevrolet Silverado, 2024 Chevrolet Silverado 2500HD, 2023 Chevrolet Silverado 2500HD, 2022 Chevrolet Silverado 2500HD, 2021 Chevrolet Silverado 2500HD, 2020 Chevrolet Silverado 2500HD, 2019 Chevrolet Silverado 2500HD, 2018 Chevrolet Silverado 2500HD, 2017 Chevrolet Silverado 2500HD, 2016 Chevrolet Silverado 2500HD, 2024 Chevrolet Silverado 3500HD, 2023 Chevrolet Silverado 3500HD, 2022 Chevrolet Silverado 3500HD, 2021 Chevrolet Silverado 3500HD, 2020 Chevrolet Silverado 3500HD, 2019 Chevrolet Silverado 3500HD, 2018 Chevrolet Silverado 3500HD, 2017 Chevrolet Silverado 3500HD, 2016 Chevrolet Silverado 3500HD, 2020 Chevrolet Sonic, 2019 Chevrolet Sonic, 2018 Chevrolet Sonic, 2017 Chevrolet Sonic, 2016 Chevrolet Sonic, 2022 Chevrolet Spark, 2021 Chevrolet Spark, 2020 Chevrolet Spark, 2019 Chevrolet Spark, 2018 Chevrolet Spark, 2017 Chevrolet Spark, 2016 Chevrolet Spark, 2024 Chevrolet Suburban, 2023 Chevrolet Suburban, 2022 Chevrolet Suburban, 2021 Chevrolet Suburban, 2020 Chevrolet Suburban, 2019 Chevrolet Suburban, 2018 Chevrolet Suburban, 2017 Chevrolet Suburban, 2016 Chevrolet Suburban, 2024 Chevrolet Tahoe, 2023 Chevrolet Tahoe, 2022 Chevrolet Tahoe, 2021 Chevrolet Tahoe, 2020 Chevrolet Tahoe, 2019 Chevrolet Tahoe, 2018 Chevrolet Tahoe, 2017 Chevrolet Tahoe, 2016 Chevrolet Tahoe, 2024 Chevrolet Trailblazer, 2023 Chevrolet Trailblazer, 2022 Chevrolet Trailblazer, 2021 Chevrolet Trailblazer, 2024 Chevrolet Traverse, 2023 Chevrolet Traverse, 2022 Chevrolet Traverse, 2021 Chevrolet Traverse, 2020 Chevrolet Traverse, 2019 Chevrolet Traverse, 2018 Chevrolet Traverse, 2017 Chevrolet Traverse, 2016 Chevrolet Traverse, 2024 Chevrolet Trax, 2022 Chevrolet Trax, 2021 Chevrolet Trax, 2020 Chevrolet Trax, 2019 Chevrolet Trax, 2018 Chevrolet Trax, 2017 Chevrolet Trax, 2016 Chevrolet Trax, 2019 Chevrolet Volt, 2018 Chevrolet Volt, 2017 Chevrolet Volt, 2016 Chevrolet Volt.
Also filed against model years this site has no page for: 2024 Chevrolet 3500HD; 2016 Chevrolet 4500; 2017 Chevrolet 4500; 2018 Chevrolet 4500; 2019 Chevrolet 4500; 2020 Chevrolet 4500; 2022 Chevrolet 4500; 2017 Chevrolet 4500HD; 2018 Chevrolet 4500HD; 2019 Chevrolet 4500HD; 2020 Chevrolet 4500HD; 2021 Chevrolet 4500HD; 2022 Chevrolet 4500HD; 2023 Chevrolet 4500HD; 2017 Chevrolet 4500XD; 2018 Chevrolet 4500XD; 2019 Chevrolet 4500XD; 2020 Chevrolet 4500XD; 2021 Chevrolet 4500XD; 2022 Chevrolet 4500XD; 2017 Chevrolet 5500HD; 2018 Chevrolet 5500HD; 2019 Chevrolet 5500HD; 2020 Chevrolet 5500HD; 2021 Chevrolet 5500HD; 2022 Chevrolet 5500HD; 2023 Chevrolet 5500HD; 2018 Chevrolet 5500XD; 2019 Chevrolet 5500XD; 2020 Chevrolet 5500XD; 2021 Chevrolet 5500XD; 2022 Chevrolet 5500XD; 2019 Chevrolet 6500; 2019 Chevrolet 6500HD; 2020 Chevrolet 6500HD; 2021 Chevrolet 6500HD; 2022 Chevrolet 6500HD; 2023 Chevrolet 6500HD; 2018 Chevrolet C3500; 2016 Chevrolet Caprice; 2017 Chevrolet Caprice; 2018 Chevrolet Caprice; 2016 Chevrolet Caprice Police Pursuit; 2017 Chevrolet Caprice Police Pursuit; 2016 Chevrolet Captiva; 2017 Chevrolet Captiva; 2018 Chevrolet Captiva; 2018 Chevrolet G4500; 2016 Chevrolet LOW Cab Forward 3500; 2017 Chevrolet LOW Cab Forward 3500; 2018 Chevrolet LOW Cab Forward 3500; 2019 Chevrolet LOW Cab Forward 3500; 2016 Chevrolet LOW Cab Forward 4500; 2017 Chevrolet LOW Cab Forward 4500; 2016 Chevrolet LOW Cab Forward 5500; 2017 Chevrolet LOW Cab Forward 5500; 2018 Chevrolet LOW Cab Forward 6500; 2016 Chevrolet N300; 2018 Chevrolet N300; 2017 Chevrolet N300 MAX and 9 more.
GMC 75 model years
and 64 more on this site: 2016 GMC Acadia, 2024 GMC Canyon, 2023 GMC Canyon, 2022 GMC Canyon, 2021 GMC Canyon, 2020 GMC Canyon, 2019 GMC Canyon, 2018 GMC Canyon, 2017 GMC Canyon, 2016 GMC Canyon, 2024 GMC Savana, 2023 GMC Savana, 2022 GMC Savana, 2021 GMC Savana, 2020 GMC Savana, 2019 GMC Savana, 2018 GMC Savana, 2017 GMC Savana, 2016 GMC Savana, 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, 2018 GMC Sierra 2500HD, 2017 GMC Sierra 2500HD, 2016 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, 2018 GMC Sierra 3500HD, 2017 GMC Sierra 3500HD, 2016 GMC Sierra 3500HD, 2024 GMC Terrain, 2023 GMC Terrain, 2022 GMC Terrain, 2021 GMC Terrain, 2020 GMC Terrain, 2019 GMC Terrain, 2018 GMC Terrain, 2017 GMC Terrain, 2016 GMC Terrain, 2024 GMC Yukon, 2023 GMC Yukon, 2022 GMC Yukon, 2021 GMC Yukon, 2020 GMC Yukon, 2019 GMC Yukon, 2018 GMC Yukon, 2017 GMC Yukon, 2016 GMC Yukon.
Also filed against model years this site has no page for: 2024 GMC 3500HD; 2017 GMC G3500; 2018 GMC G3500.
Buick 44 model years
and 35 more on this site: 2020 Buick Enclave, 2019 Buick Enclave, 2018 Buick Enclave, 2017 Buick Enclave, 2016 Buick Enclave, 2024 Buick Encore, 2023 Buick Encore, 2022 Buick Encore, 2021 Buick Encore, 2020 Buick Encore, 2019 Buick Encore, 2018 Buick Encore, 2017 Buick Encore, 2016 Buick Encore, 2024 Buick Envision, 2023 Buick Envision, 2022 Buick Envision, 2021 Buick Envision, 2020 Buick Envision, 2019 Buick Envision, 2018 Buick Envision, 2017 Buick Envision, 2016 Buick Envision, 2024 Buick Envista, 2019 Buick LaCrosse, 2018 Buick LaCrosse, 2017 Buick LaCrosse, 2016 Buick LaCrosse, 2020 Buick Regal, 2019 Buick Regal, 2018 Buick Regal, 2017 Buick Regal, 2016 Buick Regal, 2017 Buick Verano, 2016 Buick Verano.
Also filed against model years this site has no page for: 2020 Buick Lacrosse.
Cadillac 64 model years
and 52 more on this site: 2023 Cadillac CT4, 2022 Cadillac CT4, 2021 Cadillac CT4, 2020 Cadillac CT4, 2024 Cadillac CT5, 2023 Cadillac CT5, 2022 Cadillac CT5, 2021 Cadillac CT5, 2020 Cadillac CT5, 2020 Cadillac CT6, 2019 Cadillac CT6, 2018 Cadillac CT6, 2017 Cadillac CT6, 2016 Cadillac CT6, 2019 Cadillac CTS, 2018 Cadillac CTS, 2017 Cadillac CTS, 2016 Cadillac CTS, 2018 Cadillac CTS-V, 2024 Cadillac Escalade, 2023 Cadillac Escalade, 2022 Cadillac Escalade, 2021 Cadillac Escalade, 2020 Cadillac Escalade, 2019 Cadillac Escalade, 2018 Cadillac Escalade, 2017 Cadillac Escalade, 2016 Cadillac Escalade, 2016 Cadillac SRX, 2024 Cadillac XT4, 2023 Cadillac XT4, 2022 Cadillac XT4, 2021 Cadillac XT4, 2020 Cadillac XT4, 2019 Cadillac XT4, 2024 Cadillac XT5, 2023 Cadillac XT5, 2022 Cadillac XT5, 2021 Cadillac XT5, 2020 Cadillac XT5, 2019 Cadillac XT5, 2018 Cadillac XT5, 2017 Cadillac XT5, 2024 Cadillac XT6, 2023 Cadillac XT6, 2022 Cadillac XT6, 2021 Cadillac XT6, 2020 Cadillac XT6, 2019 Cadillac XTS, 2018 Cadillac XTS, 2017 Cadillac XTS, 2016 Cadillac XTS.
Also filed against model years this site has no page for: 2021 Cadillac CT6; 2018 Cadillac XT4; 2016 Cadillac XT5; 2020 Cadillac XTS.
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 330 model years this bulletin names have filed 40,845 complaints with NHTSA since 2015. 21,269 of them name Engine, Power Train — 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 2016 Chevrolet Malibu, the 173 owners who gave an odometer reading for Engine reported it at a median of 53,000 miles. That figure is one model year’s, not the whole range this bulletin covers — medians from different model years are not averaged.
I Took My Car To Castle Villa Park On July 8 2025 And Explained To Tony That Check My Car In That It Sound As If It Was A Hub Bearing My Car Was Dropped Off At 7:00 AM Until Around 1:00PM I Was Told I Need A Tire To See If It Was My Hub Bearing Which Didn’t Make Sense To Me So I Ask For A Supervisor I Was Then Inform That They Could Tell…
2020 Chevrolet Impala · Power Train · filed with NHTSA Jul 20, 2025 · ODI 11674888
Sudden jerk power train and deceleration while driving and towing 5th wheel, immediate loss of power and could have been catastrophic. GM has a known defect that requires immediate attention and investigation to affirm this is a broad national problem with the Allison 10 speed 10L1000 transmission, specifically the defective transmission…
2023 Chevrolet Silverado 2500HD · Power Train · filed with NHTSA Jul 8, 2025 · ODI 11671999
On July 5, 2024 while traveling and towing our 5th wheel (7,200lbs) with our 2017 GMC 2500 6.0L GAS engine (with the 6L90 transmission) and without any previous warnings or signals the check engine light illuminated and approximately 10 mins later the vehicle went into limp mode with "Transmission Hot.....Idle Engine" warning, causing us…
2017 GMC Sierra 2500HD · Power Train · filed with NHTSA Jul 16, 2024 · ODI 11602719
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 group388 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… |
| 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… |
| 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… |
| 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… |
| N242484750-02 | Warranty extension | Sep 1, 2026 | Special Coverage. Certain 2022 model year Buick Encore GX and Chevrolet Trailblazer vehicles, equipped with a 1.2L engine, may have a condi… |
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 PI1394B 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 PI1394B 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 PI1394B cover?
The manufacturer filed it against 407 model years across 4 brands (Chevrolet, GMC, Buick and Cadillac): 2019 Buick Cascada, 2018 Buick Cascada, 2017 Buick Cascada, 2016 Buick Cascada, 2024 Buick Enclave, 2023 Buick Enclave and more. Whether one particular vehicle is affected is a matter of its VIN and its build, not its model year alone.