See also:

Compass Calibration Procedure
1. Before calibrating the compass, check that the compass is set to the correct variance zone. See “Compass Variance (Zone) Procedure” earlier in this section. Do not operate any switches ...

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 ...

Tire Pressure Light
For vehicles with the Tire Pressure Monitor System (TPMS), this light comes on briefly when the engine is started. It provides information about tire pressures and the TPMS. When the Light Is ...