GM bulletin 23-NA-091
What it saysThis service bulletin provides information for dealers/technicians on Rough Idle, Malfunction Indicator Lamp (MIL) Illuminated After Engine Repairs with DTCs P0016 and/or P0018 Set. NHTSA’s full summary ↓
GM filed this with NHTSA as a service bulletin dated May 11, 2023, received May 13, 2023, about the engine. It names 45 model years across Chevrolet, GMC and Cadillac (2016–2023). 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 · Cadillac.
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What the bulletin says
Source: NHTSA's summary of the manufacturer's communicationThis service bulletin provides information for dealers/technicians on Rough Idle, Malfunction Indicator Lamp (MIL) Illuminated After Engine Repairs with DTCs P0016 and/or P0018 Set.
Trouble codes it names: P0016 P0018
Document filed under this number
| Document | Kind | Dated | NHTSA id | At NHTSA |
|---|---|---|---|---|
| 23-NA-091 | Service bulletin | May 11, 2023 | 10236106 | 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 11 model years
GMC 10 model years
Cadillac 24 model years
and 5 more on this site: 2017 Cadillac XT5, 2023 Cadillac XT6, 2022 Cadillac XT6, 2021 Cadillac XT6, 2020 Cadillac XT6.
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 45 model years this bulletin names have filed 3,667 complaints with NHTSA since 2015. 1,347 of them name Electrical System, 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 110 owners who gave an odometer reading for Electrical System reported it at a median of 35,000 miles. That figure is one model year’s, not the whole range this bulletin covers — medians from different model years are not averaged.
Transmission slipped almost from start. Took three appointments and two years - If my shop foreman knew the third time, why did he not call and tell me we now know your problem. I finally got fed up and brought it in one more time. Starter from day ONE maybe 50% of time made loud bang when Bendix retracted. Shop refused to take it off!!!
2018 GMC Canyon · Engine · filed with NHTSA Jan 1, 2022
I have taken this vehicle to Chevrolet dealerships approx. 8 different times due to malfunction of this vehicle. I have contacted general motors this vehicle started these problems 1 month after I purchased it when I purchased it ,it only had 95 miles on it, in the mean time due to general motors closing the case and not willing to fix…
2016 Chevrolet Camaro · Electrical System · filed with NHTSA Jun 19, 2018
GM had a recall on the 3.6 lgz equipped in trucks in canada. Cold weather caused oil pump to over pressurizing of oil and damage to oil cooler and lines. Leaking oil in to engine compartment and on roadway. This has happened to me twice now once in march of 2018 and now again in november 2019. Doing research this is a common complaint.
2017 GMC Canyon · Engine · filed with NHTSA Nov 20, 2019
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 group134 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 |
|---|---|---|---|
| N262570770-02 | 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… |
| 22-NA-080 | Service bulletin | Sep 6, 2025 | This technical bulletin provides a procedure to replace the camshaft actuator magnet to correct customer concerns of engine related shudder. |
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 23-NA-091 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 23-NA-091 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.
Which vehicles does 23-NA-091 cover?
The manufacturer filed it against 45 model years across 3 brands (Chevrolet, GMC and Cadillac): 2019 Cadillac ATS, 2018 Cadillac ATS, 2017 Cadillac ATS, 2016 Cadillac ATS, 2020 Cadillac CT6, 2019 Cadillac CT6 and more. Whether one particular vehicle is affected is a matter of its VIN and its build, not its model year alone.