See also:

When to Check and Change Lubricant
It is not necessary to regularly check front axle fluid unless there is a leak suspected or an unusual noise is heard. A fluid loss could indicate a problem. Have it inspected and repaired. ...

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 ...

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 ...