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Over-the-air update 661.30

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 id11031807
Published by NHTSA2026-04-30
Manufacturer's number661.30
Manufacturer's date2026-04-14
Campaign id or software version661.30
NHTSA componentUNKNOWN OR OTHER
Manufacturer's systemECM: ECM (Engine Control Module)

NHTSA's summary

• Fixes to help extend coolant valve life through diagnostic changes.

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
CHEVROLET SILVERADO 15002023 (the catalog's model; the bulletin names a series or trim of it)
GMC SIERRA 15002023 (the catalog's model; the bulletin names a series or trim of it)

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