OnStar Vehicle Diagnostics can perform a vehicle check every month. It will check
the engine, transmission, antilock brakes, and other major vehicle systems. It also
checks the tire pressures, if the vehicle is equipped with the Tire Pressure Monitoring
System. If an On-Demand Diagnostics check is needed, press
, and an Advisor can run a check.
Connections
OnStar Additional InformationTire Pressure
Tires need the correct amount of air pressure to operate effectively.
Caution
Neither tire underinflation nor overinflation is good.
Underinflated tires, or tires that do not have enough air, can result in:
Tire overloading and overheating which could lead to a blowout.
Premature or irregul ...
Starting the Engine
Automatic Transmission
Move the shift lever to P (Park) or N (Neutral). The engine will not start in
any other position. To restart the engine when the vehicle is already moving, use
N (Neutral) only.
Caution
Do not try to shift to P (Park) if the vehicle is moving. If you
do, you could dam ...
If Steam Is Coming from the Engine Compartment
Warning
Steam from an overheated engine can burn you badly, even if you
just open the hood. Stay away from the engine if you see or hear steam coming from
it. Just turn it off and get everyone away from the vehicle until it cools down.
Wait until there is no sign of steam or coolant before you ...