One problem related to front seat head restraint has been reported for the 1999 GMC Sierra. The most recently reported issues are listed below.
Driver's passive restraint is inoperable. Restraint has locked in one position. The dealer has repaired and replaced the restraint previously. Manufacturer has been notified. Also, mechanism that locks the driver's seat in the track broke while driving, almost caused loss of control.
| Seats problems | |
| Seat Broken problems | |
| Front Seat Recliner problems | |
| Front Seat Power Adjust problems | |
| Front Seat Head Restraint problems | |
| Mid/rear Seats Assembly problems |