Chevrolet Silverado 1500 2023 — technical service bulletin
Bulletin 661.30 · NHTSA communication 11031807 · issued Apr 14, 2026
Technical service bulletin
communication type
Unknown OR Other
component
2023
model years
2
vehicle entries
Official summary
• Fixes to help extend coolant valve life through diagnostic changes.
Vehicles covered
What a TSB means. Technical service bulletins are repair guidance manufacturers send to dealers — they are not recalls, and repairs are not automatically free (warranty extensions are an exception worth checking). The full document is available via NHTSA’s vehicle lookup.