See also:

Adaptive Forward Lighting (AFL) Light
This light should come on briefly as the vehicle is started. If it does not come on, have the vehicle serviced by your dealer. This light comes on solid when there is a problem with the Adapti ...

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 v ...

TPMS Sensor Matching Process
Each TPMS sensor has a unique identification code. The identification code needs to be matched to a new tire/wheel position after rotating the vehicle’s tires or replacing one or more of the TPMS ...