GMC over-the-air update N25-251670
What it saysImprovements to battery health diagnostics Fixes for efficiency when using fast charging stations Improvements to reliability for climate control and charging Improvements to the accuracy of efficiency values… NHTSA’s full summary ↓
GMC filed this with NHTSA as an over-the-air update dated Sep 30, 2025, received Oct 1, 2025 — 2 documents under this number. It names 3 model years (2024–2025). An over-the-air update 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.
Get the next GMC bulletin for your model by email Weekly, only when something new is filed. Nothing else; one-click unsubscribe.
What the bulletin says
Source: NHTSA's summary of the manufacturer's communication• Improvements to battery health diagnostics • Fixes for efficiency when using fast charging stations • Improvements to reliability for climate control and charging • Improvements to the accuracy of efficiency values • Improvements to shifting • Fixes to protect battery health and adjust charge limits • Improvements to diagnostics that impact propulsion, charging, and One-Pedal Driving During the update process, your radio may stay on up to 5 minutes after you exit the vehicle. This is expected behavior when an update package is onboard the vehicle. Do not service your vehicle during installation.
Documents filed under this number
| Document | Kind | Dated | NHTSA id | At NHTSA |
|---|---|---|---|---|
| N25-251670 | Over-the-air update | Sep 30, 2025 | 11023418 | PDF, 102 KB |
| N25-251670 | Over-the-air update | Sep 30, 2025 | 11023410 | PDF, 102 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.
Email me new GMC bulletins for one of these models
A weekly email, sent only in a week when GMC files something new with NHTSA for the model you pick — service bulletins, campaigns, warranty extensions, over-the-air notices, every model year. Nothing else is sent; one-click unsubscribe in every message. Separate from recall alerts.
What owners reported
Source: NHTSA complaint databaseOwners of the 3 model years this bulletin names have filed 162 complaints with NHTSA since 2015.
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.
Quote the number at the service desk. It is what the dealer’s system is keyed on.
Every manufacturer communication NHTSA holds for GMC, by the number printed on the letter.
Common questions
Source: NHTSA, 49 CFR 579.5Is GMC N25-251670 a recall?
No. A over-the-air update 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 N25-251670 repair free?
A over-the-air update 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 N25-251670 cover?
The manufacturer filed it against 3 model years: 2025 GMC Hummer EV, 2024 GMC Hummer EV, 2025 GMC Sierra. Whether one particular vehicle is affected is a matter of its VIN and its build, not its model year alone.