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 InformationCleaning Exterior Lamps/ Lenses, Emblems, Decals and Stripes
Use only lukewarm or cold water, a soft cloth, and a car washing soap to clean
exterior lamps, lenses, emblems, decals and stripes. Follow instructions under "Washing
the Vehicle" previously in this section.
Lamp covers are made of plastic, and some have a UV protective coating. Do no ...
Vehicle Messages
DIC messages display when the status of the vehicle has changed and action may
be needed to correct the condition. Multiple messages appear one after another.
All messages should be taken seriously.
Vehicle messages appear as code numbers. The owner manual indicator and service
vehicle soon li ...
Brake Fluid
The brake/clutch master cylinder
reservoir is filled with DOT 4 brake fluid as indicated on the reservoir cap. See
Engine Compartment Overview on page 10-7 for the location of the reservoir.
There are only two reasons why the brake fluid level in the reservoir might go
down:
The brake fl ...