GM service campaign N252502891-01
What it saysCertain vehicles may have a condition in which the internal differential nut was cross threaded or missing during assembly. NHTSA’s full summary ↓
GM filed this with NHTSA as a service campaign dated Aug 20, 2026, about the power train. It names 8 model years across Chevrolet, GMC, Cadillac and Brightdrop (2024–2025). A service campaign is not a safety recall — there is no NHTSA campaign number and no federal requirement — but it is usually work the manufacturer pays for on the vehicles it names; the dealer checks the VIN against the manufacturer’s list.
One page for every brand it was filed under. Each brand’s bulletins: Chevrolet · GMC · Cadillac · Brightdrop.
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What the bulletin says
Source: NHTSA's summary of the manufacturer's communicationPicked out of NHTSA’s summary below, word for word. The document itself is the record, and the dealer checks the VIN.
Certain vehicles may have a condition in which the internal differential nut was cross threaded or missing during assembly. Dealers will review the vehicles service history in IVH, and if necessary, replace the rear electric drive transmission module.
Document filed under this number
| Document | Kind | Dated | NHTSA id | At NHTSA |
|---|---|---|---|---|
| N252502891-01 | Service campaign | Aug 20, 2026 | 11036308 | PDF, 311 KB |
What the document itself lists
The manufacturer titles it “UPDATE: N252502890-01, N252502891-01 - Customer Satisfaction Program”.
Parts the bulletin names
| Part number | Description | Qty |
|---|---|---|
| 24070676 | MODULE, RR ELEC DRV TRANSAXLE | — |
| 24295033 | GASKET-DRV MOT PWR INV MDL CVR | — |
| 24043423 | COVER ASM-DRV MOT PWR INV MDL | — |
| 24050273 | PIPE ASM-TRANS FLUID CLR | — |
| 24297800 | FITTING-DRV MOT CONT MDL CLG OTLT HOSE | — |
| 11589358 | BOLT, RR S/ABS | — |
| 11610909 | BOLT, RR SUSP LINK | — |
| 11609606 | BOLT, RR SUSP TRAILING ARM | — |
| 11610884 | BOLT, RR SUSP UPR CONT ARM INR | — |
| 11603529 | BOLT, RR DRV MOT RR MT | — |
| 11589282 | BOLT, RR DRV MOT MT | — |
| 11609605 | BOLT, RR DRV MOT MT (LYRIQ Only) | — |
| 19352619 | — | — |
| 19352620 | — | — |
| 12378390 | — | — |
| 10953456 | Customer Satisfaction Program | — |
| 11571089 | BOLT, RR DRV MOT RR MT | — |
| 11517236 | BOLT, RR DRV MOT MT | — |
| 11612295 | NUT, RR WHL DRV SHF | — |
| 11605101 | WASHER, FRT WHL DRV SHF | — |
| 11604512 | BOLT/SCREW-DIFF CARR FRT | — |
| 11570788 | BOLT, RR BRK CLPR BRKT | — |
| 11610880 | BOLT, RR AXLE KNU | — |
Labour operation and the time the manufacturer allows
| Operation | Description | Time |
|---|---|---|
| 9107975 | Inspect VIN in IVH, No Further Action Required | 0.2 hrs |
Read by machine from the document NHTSA serves (5 pages), read Sep 30, 2026. A part number is shown only where it matches GM’s own catalogue shape, an operation only with its code and time, and a description only where the reader got it whole; anything it could not settle is left out, and the PDF is the record. Times are the manufacturer’s warranty allowances, not a quote.
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 3 model years
Also filed against model years this site has no page for: 2025 Chevrolet Brightdrop 600.
GMC 1 model year
Cadillac 3 model years
Brightdrop 1 model year
Also filed against: 2024 Brightdrop Zevo 400.
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 6 model years this bulletin names have filed 767 complaints with NHTSA since 2015. 132 of them name 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 2024 Chevrolet Silverado, the 13 owners who gave an odometer reading for Power Train reported it at a median of 10,900 miles. That figure is one model year’s, not the whole range this bulletin covers — medians from different model years are not averaged.
While driving northbound on , south of Oklahoma City, at normal highway speed, at night, in the rain (on ), this EV lost all power to the wheels and the regenerative braking ceased to function. It appears that all flow of electrons from the batteries to the drive motors, and from the regenerative brakes to the batteries stopped.
2024 Cadillac Lyriq · Power Train · filed with NHTSA Nov 4, 2024 · ODI 11623497
The contact owned a 2024 Chevrolet Silverado EV. The contact stated that when idle, the vehicle would hesitate before accelerating. Continuing to drive at approximately 55 MPH, the accelerator was released, and the vehicle continued to accelerate.
2024 Chevrolet Silverado · Power Train · filed with NHTSA Nov 18, 2025 · ODI 11700039
The transmission in my 2024 Chevrolet Blazer is very noisy often making whining and grinding sounds and I experience rough shifting and transmission hesitation during acceleration or gear changes
2024 Chevrolet Blazer · Power Train · filed with NHTSA Sep 22, 2025 · ODI 11688917
In depth: 2024 Chevrolet Silverado transmission and drivetrain 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 power train
Source: same model, same component group118 other manufacturer communications filed against these GM models under the same component group (power train), newest first. The eight newest are listed; the rest are on the Chevrolet list.
| Number | Kind | Dated | NHTSA’s summary |
|---|---|---|---|
| N252502890-01 | Service campaign | Aug 20, 2026 | Certain vehicles may have a condition in which the internal differential nut was cross threaded or missing during assembly. Dealers will rev… |
| N242471460-01 | Service campaign | Aug 20, 2026 | Certain vehicles may have been built with an Electric Drive Unit mounting bolt that is too long, causing damage to the Drive Unit case. Deal… |
| N252517790 | Service campaign | Oct 14, 2025 | Certain vehicles, equipped with 8L80 or 8L90 Transmissions, may have a condition in which the reaction carrier cracks. Dealers are to replac… |
| N242454441 -03 | Service campaign | Oct 9, 2025 | Certain vehicles listed above, may have a condition where the transmission control valve has worn, resulting in a gradual loss of pressure w… |
| 25-NA-080 | Service bulletin | Sep 4, 2025 | This service bulletin provides a procedure to overhaul the control valve to replace a plate and worn down check ball to correct the customer… |
| N252494003-01 | Service campaign | Jun 26, 2025 | Certain vehicles listed above, may have a condition where the connecting rod and/or crankshaft engine components in these vehicles may have… |
| N242483540-01 | Service campaign | May 21, 2025 | Certain vehicles listed above may have a condition in which the transmission may not shift properly. Dealers are to replace the transmission… |
| 22-NA-182 | Service bulletin | May 16, 2025 | This service bulletin advises the technician to check if the transmission cooler lines are twisted to correct customer concerns of Harsh Shi… |
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, Cadillac and Brightdrop, by the number printed on the letter.
Common questions
Source: NHTSA, 49 CFR 579.5Is GM N252502891-01 a recall?
No. A service campaign 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 N252502891-01 repair free?
A service campaign is usually paid by the manufacturer on the vehicles it names, within the terms and time limit the document sets; the dealer checks the VIN against the manufacturer’s list.
Which vehicles does N252502891-01 cover?
The manufacturer filed it against 8 model years across 4 brands (Chevrolet, GMC, Cadillac and Brightdrop): 2025 Cadillac Escalade, 2025 Cadillac Lyriq, 2024 Cadillac Lyriq, 2024 Chevrolet Blazer, 2024 Chevrolet Silverado, 2025 GMC Sierra and more. Whether one particular vehicle is affected is a matter of its VIN and its build, not its model year alone.