The vehicle brake system consists of two hydraulic circuits. If one circuit is not working, the remaining circuit can still work to stop the vehicle. For normal braking performance, both circuits need to be working
If the warning light comes on, there is a brake problem. Have the brake system inspected right away.
Warning:
The brake system might not be working properly if the brake system warning light is on. Driving with the brake system warning light on can lead to a crash. If the light is still on after the vehicle has been pulled off the road and carefully stopped, have the vehicle towed for service.

This light should come on briefly when the ignition is turned to ON. If it does not come on then, have it fixed so it will be ready to warn if there is a problem.
When the ignition is on, the brake system warning light will also come on when the parking brake is set. The light will stay on if the parking brake does not fully release. If it stays on after the parking brake is fully released, it means there is a brake problem.
If the light comes on while driving, carefully pull off the road and stop. The pedal may be harder to push or may go closer to the floor. It may take longer to stop. If the light is still on, have the vehicle towed for service. See Towing the Vehicle.
Brake System External Leak Inspection
Brake Warning System Description and OperationCleaning 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 and emblems. Follow instructions under "Washing the Vehicle"
previously in this section.
Lamp covers are made of plastic, and some have a UV protective coating.
Use only lukewarm wat ...
Door Lock and Ignition Lock Folding and Non-Folding Key Cutting
High Security keys are available from the service parts system.
Obtain the key code from the security card or from the GM Dealer World, Parts,
Key Code Look Up system.
If you have the key code and access to a Triax-E., BD Laser or other code key
cutting machine from the GM Dealer Equipment C ...
Camshaft Position Actuator Adjuster Installation
Special Tools
EN-6340 Camshaft Adjuster Locking Tool
EN-6628-A Camshaft Locking Tool
EN-45059 Angle Meter
For equivalent regional tools, refer to Special Tools.
Note: Note the arrows.
Turn the camshaft by the hexagon until the groove on the end of the camshafts
is ...