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HomeBulletinsGMC 662.11
Manufacturer communication · Over-the-air update

GMC bulletin 662.11

GMC filed this with NHTSA as a over-the-air update dated Jul 23, 2026, received Jul 8, 2026, about the unknown or other — 3 documents under this number. It names 5 model years (2024–2026). A 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.

What the bulletin says

Source: NHTSA's summary of the manufacturer's communication

• Fixes to help ensure proper functionality for shifting. • Fixes to help protect transmission health. • Improvements to diagnostics to prevent vehicle not starting. • Fixes to help reduce instances of check engine light activation in cold weather.

Manufacturer campaign id 662.11 Kind Over-the-air update Manufacturer date Jul 23, 2026 Received by NHTSA Jul 8, 2026 Components Unknown Or Other First dated Jun 15, 2026

Documents filed under this number

DocumentKindDatedNHTSA id
662.11Over-the-air updateJul 23, 202611035452
662.11Over-the-air updateJul 14, 202611035427
662.11Over-the-air updateJun 15, 202611034928

The summary is NHTSA’s abstract of the document, as filed under 49 CFR 579.5; the full text comes from the manufacturer or a dealer. 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. Quote it at a service desk; it is what the dealer’s system is keyed on.

Model years it names

Source: as the manufacturer filed them

Also filed against model years this site has no page for: 2026 GMC Hummer EV Pickup; 2026 GMC Hummer EV SUV.

A vehicle page’s bulletin list shows the newest few communications filed against that model year; the count there is every one.

Common questions

Source: NHTSA, 49 CFR 579.5

Is GMC 662.11 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 662.11 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 662.11 cover?

The manufacturer filed it against 5 model years: 2025 GMC Acadia, 2024 GMC Acadia, 2026 GMC Sierra 2500HD, 2026 GMC Hummer EV Pickup, 2026 GMC Hummer EV SUV. Whether one particular vehicle is affected is a matter of its VIN and its build, not its model year alone.