TSB 661.51 — Chevrolet and GMC Software update
661.51 is a software update on file with NHTSA for 2 Chevrolet and GMC models, 2024 model years. A TSB is factory repair guidance, not a recall — the repair is not automatically free.
What the bulletin says. • Fixes to help ensure proper functionality for heating and cooling features. • Improvements to night mode lights for shifting gears. • Fixes for Daytime Running Lamps turning on when set to Off. • Fixes to help prevent erroneous missing key messages on driver display. • Fixes…
NHTSA's own summary of the document, quoted from the public manufacturer-communications file.
Worth checking your VIN against. 661.51 is filed as a software update, which unlike an ordinary bulletin can mean free or reimbursed work when a vehicle qualifies. Ask a dealer using the document ID below, and check open recalls separately at nhtsa.gov/recalls.
Vehicles and model years 661.51 names
| Vehicle | Model years |
|---|---|
| Chevrolet Silverado 1500 | 2024 |
| GMC Sierra 1500 | 2024 |
Every document filed under 661.51
| Document ID | Filed | Type |
|---|---|---|
| 661.51 | June 9, 2026 | Software update |
Questions buyers ask
What is TSB 661.51?
661.51 is a software update filed with NHTSA by Chevrolet and GMC, covering 2 Chevrolet and GMC models across the 2024 model years. NHTSA's summary reads: • Fixes to help ensure proper functionality for heating and cooling features. • Improvements to night mode lights for shifting gears. • Fixes for Daytime Running Lamps turning on when set to Off. • Fixes to help prevent erroneous missing key messages on driver display. • Fixes…
Which vehicles does 661.51 cover?
NHTSA's file names Chevrolet Silverado 1500 (2024); GMC Sierra 1500 (2024). A bulletin number can be re-issued against more vehicles later, so check the model-year list on this page against your own.
Is TSB 661.51 a recall, and is the repair free?
661.51 is filed as a software update, not a recall — but this is the kind of communication that can mean free or reimbursed work if your VIN qualifies. Take the number to a dealer and ask. Recalls are separate and always free; check yours by VIN at nhtsa.gov/recalls.
How do I get the full text of 661.51?
Take the document ID to a dealer's service desk, or search NHTSA's manufacturer-communications records. This page carries every document ID filed under 661.51, its date, and NHTSA's own summary from the public file.
Every number on this page is a count of records in the federal complaint, recall, and investigation files published by NHTSA's Office of Defects Investigation. This page lists only what NHTSA's manufacturer-communications file records under 661.51. Check any specific vehicle's open recalls by VIN at nhtsa.gov/recalls.