Cadillac bulletin 23-NA-121
What it saysThis technical bulletin provides a procedure to correct Squeal/Whine Noises Underneath Vehicle at Highway Speeds. NHTSA’s full summary ↓
Cadillac filed this with NHTSA as a service bulletin dated Jul 13, 2023, received Jul 25, 2023, about the power train. It names 8 model years (2020–2023). 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.
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What the bulletin says
Source: NHTSA's summary of the manufacturer's communicationThis technical bulletin provides a procedure to correct Squeal/Whine Noises Underneath Vehicle at Highway Speeds.
Document filed under this number
| Document | Kind | Dated | NHTSA id | At NHTSA |
|---|---|---|---|---|
| 23-NA-121 | Service bulletin | Jul 13, 2023 | 10239641 | PDF, 70 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 themA 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 8 model years this bulletin names have filed 159 complaints with NHTSA since 2015. 59 of them name Power Train, 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 September 15,2026, my vehicle experienced a catastrophic los of power steering assist accompanied by severe heavy steering. Please review General Motors TSB 20-NA-215 & TSB 17-NA-158 both addressing this issue. My 2021 vehicle has a build date of September 19, 2020 which falls "directly" in the time frame covered by these bulletins.
2021 Cadillac XT6 · Electrical System · filed with NHTSA Oct 11, 2026 · ODI 11770401
The contact owns a 2023 Cadillac XT5. The contact stated that upon shifting into reverse(R), the vehicle intermittently failed to respond. The contact stated that the failure had progressively worsened, and the vehicle responded after an extended period. The vehicle was taken to the dealer; however, the failure was not duplicated.
2023 Cadillac XT5 · Power Train · filed with NHTSA Oct 5, 2026 · ODI 11769127
The contact owns a 2023 Cadillac XT6. The contact stated while driving at an undisclosed speed, the vehicle lost motive power. The contact was able to pull to the shoulder of the roadway, where the vehicle failed to restart. No warning lights were illuminated. The vehicle was not taken to the dealer or an independent mechanic.
2023 Cadillac XT6 · Power Train · filed with NHTSA Aug 14, 2024 · ODI 11608604
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 power train
Source: same model, same component group33 other manufacturer communications filed against these Cadillac models under the same component group (power train), newest first. The eight newest are listed; the rest are on the Cadillac list.
| Number | Kind | Dated | NHTSA’s summary |
|---|---|---|---|
| 25-NA-001 | Service bulletin | Mar 13, 2025 | This service bulletin provides repair information to correct a customer concern of a transmission fluid leak. |
| 09-06-04-026Z | Service bulletin | Jan 9, 2025 | This bulletin provides information on identifying Non-GM Engine Calibrations for Gasoline Engines using the Tech 2 or GDS 2. |
| PIP5974E | Service bulletin | Dec 5, 2024 | This Preliminary information communicates possible transmission 1-2-3-4-5-6 snap rings out of round causing code p0746 or p0747. |
| 08-07-30-035I | Service bulletin | Nov 27, 2024 | This service bulletin provides information on the harmful effects of ethylene glycol in transmission fluid. |
| PIP6025 | Service bulletin | Nov 21, 2024 | This Preliminary information communicates possible transmission fluid leak in the torque converter housing area from loose pump bolts. |
| 21-NA-181 | Service bulletin | Nov 18, 2024 | This service bulletin provides 9th gear operation information to respond to customers that may comment on transmission shift operation. |
| 23-NA-021 | Service bulletin | Oct 29, 2024 | This service bulletin advises the tech that the rotational Clicking Noise Heard After Engine Shut Down may be normal characteristics of the… |
| 04-06-01-029K | Service bulletin | Oct 28, 2024 | This informational bulletin explains Unscheduled Supplemental Services and the importance of GM Simplified Maintenance Schedules. |
Quote the number at the service desk. It is what the dealer’s system is keyed on.
Every manufacturer communication NHTSA holds for Cadillac, by the number printed on the letter.
Common questions
Source: NHTSA, 49 CFR 579.5Is Cadillac 23-NA-121 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-121 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 23-NA-121 cover?
The manufacturer filed it against 8 model years: 2023 Cadillac XT5, 2022 Cadillac XT5, 2021 Cadillac XT5, 2020 Cadillac XT5, 2023 Cadillac XT6, 2022 Cadillac XT6 and more. Whether one particular vehicle is affected is a matter of its VIN and its build, not its model year alone.