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 InformationCharging System Light
This light will come on briefly
when the ignition is turned on, and the engine is not running, as a check to show
it is working.
It should go out when the engine is started. If it stays on, or comes on while
driving, there may be a problem with the electrical charging system. Have it checked ...
Cruise Control
If equipped with cruise control, the vehicle can maintain a speed of about 40
km/h (25 mph) or more without keeping your foot on the accelerator. Cruise control
does not work at speeds below 40 km/h (25 mph).
Warning
Cruise control can be dangerous where you cannot drive safely
at a steady s ...
Driving on Wet Roads
Rain and wet roads can reduce vehicle traction and affect your ability to stop
and accelerate.
Always drive slower in these types of driving conditions and avoid driving through
large puddles and deep-standing or flowing water.
Warning
Wet brakes can cause crashes.
They might not work as wel ...