Cadillac Celestiq 2026 — technical service bulletin
Bulletin PIC6638 · NHTSA communication 11027946 · issued Jan 28, 2026
Technical service bulletin
communication type
Unknown OR Other
component
2026
model years
15
vehicle entries
Official summary
This Preliminary information communicates to the technician the repair direction needed to address an inaccurate speed limit sign displayed on instrument cluster.
Vehicles covered
- 2026 Cadillac Celestiq
- 2026 Cadillac Escalade
- 2026 Cadillac Escalade Esv
- 2026 Cadillac Escalade IQ
- 2026 Cadillac Lyriq
- 2026 Cadillac Optiq
- 2026 Cadillac Vistiq
- 2026 Chevrolet Equinox EV
- 2026 Chevrolet Silverado EV
- 2026 Chevrolet Traverse
- 2026 GMC Acadia
- 2026 GMC Hummer EV Pickup
- 2026 GMC Hummer EV SUV
- 2026 GMC Sierra EV
- 2026 GMC Yukon
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.