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Over-the-air update 663.20

A bulletin is a manufacturer's communication to its dealers, as NHTSA indexes it. The summary is NHTSA's. The document is the manufacturer's: read it at NHTSA. A bulletin is not a recall, and listing a model year does not mean every vehicle of it is concerned.

The communication, as NHTSA indexes it (as of 2026-10-19)
TypeOver-the-air update
NHTSA id11035293
Published by NHTSA2026-07-29
Manufacturer's number663.20
Manufacturer's date2026-07-16
Campaign id or software version663.20
NHTSA componentUNKNOWN OR OTHER
Manufacturer's systemTCM: TCM (Transmission Control Module)

NHTSA's summary

• Improves transmission diagnostic software. • Reduces unnecessary check engine light activations.

The document

The document is the manufacturer's. This site does not hold it. NHTSA files a document at one of these two addresses; we have not asked NHTSA which.

Vehicles listed
CADILLAC ESCALADE2025
CADILLAC ESCALADE ESV2025
CHEVROLET SUBURBAN 15002025 (the catalog's model; the bulletin names a series or trim of it)
CHEVROLET TAHOE2025
GMC YUKON2025
GMC YUKON XL2025

Listing a model year does not mean every vehicle of it is concerned: the document says which.