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 OnStar Additional Information, and an Advisor can run a check.

    See also:

    Speedometer
    The speedometer shows how fast the vehicle is moving in either kilometers per hour (km/h) or miles per hour (mph). The speedometer cannot be reset. ...

    Interior
    The Sierra showcases two different interior designs. Work Truck and SLE models are more utility-minded, with large controls and door handles that can be operated while wearing gloves. The SLT offe ...

    EQ Settings
    The EQ settings are selected through the tone menu. Press the left or right arrows to cycle through the EQ options. The available choices are Pop, Rock, Jazz, Classical, and Talk. ...