Software Update 2026–2027 Yukon/Yukon XL Software Update — 663.40/663.20

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Over-the-air software update · 663.40/663.20

This is an over-the-air software update notice. GMC filed it with NHTSA to describe a software release; it is not a recall unless it says so. Delivery depends on your vehicle's connectivity and settings.

Published: Oct 21, 2026
Applies to: Yukon, Yukon XL (2026–2027 model years)

Summary (official text)​

• Improved power window operation • Improvements to help prevent battery drain • Improved vehicle access and starting features

Sources​

• 663.40/663.20 (PDF, NHTSA document 11038832) — Oct 21, 2026

Details from NHTSA as of Nov 1, 2026. If NHTSA or GMC revises this notice, this post is updated and significant changes are noted in a reply. The linked documents are the authority, and a dealer can confirm whether it applies to your VIN.

Has this update reached your vehicle? Share your model year and anything that changed after it installed.

 

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