Diagnostics
OnStar Vehicle Diagnostics will perform a vehicle check every month. It will check the engine, transmission, antilock brakes, and major vehicle systems. It also checks the tire pressures, if the vehicle is equipped with the Tire Pressure Monitoring System. If a diagnostics check is needed between e-mails, push 
, and an Advisor can run a check.
See also:
If the Off Indicator is Lit for an Adult-Size Occupant
If a person of adult-size is sitting in the right front passenger seat, but the off indicator is lit, it could be because that person is not sitting properly in the seat. If this happens, use the fo ...
Auxiliary Taillamp
To replace one of these lamps:
1. Open the liftgate. See Liftgate on page 2‑9.
2. Remove the interior trim access panel.
A. Attachment Nuts
B. Retaining Hook
3. Remove the five attachment ...
If You Cannot See the HUD Image When the Ignition Is On
• Is anything covering the HUD lens?
• Is the HUD dimmer setting bright enough?
• Is the HUD image adjusted to the proper height?
• Are you wearing polarized sunglasses?
• Still no HUD i ...