OnStar Services

See also:

Engine & Transmission
The CTS comes standard with a 3.0-liter V-6 engine, but our test car's optional 3.6-liter V-6 and six-speed automatic transmission are a special pair among drivetrains. The transmission's shifts a ...

When the Light Flashes First and Then Is On Steady
If the light flashes for about a minute and then stays on, there may be a problem with the TPMS. If the problem is not corrected, the light will come on at every ignition cycle. See Tire Pres ...

Battery Voltage and Charging Messages
BATTERY LOW START VEHICLE When the vehicle’s battery is severely discharged, this message will display and four chimes will sound. Start the vehicle immediately. If the vehicle is not started and ...