This update contains a required software change to help improve the overall software update and...
Chevrolet technical service bulletin 663.20 for 2026 Chevrolet Silverado 1500 and 2026 GMC Sierra 1500.
- Bulletin number
- 663.20 (663.20)
- Component
- Unknown or other
- Summary
- This update contains a required software change to help improve the overall software update and diagnostics process. Be sure to install this update to be able to receive future software updates.
Vehicles covered
- Chevrolet Silverado 1500 2026 2026
- GMC Sierra 1500 2026 2026
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