2011 Chevrolet Volt Owner's Manual - Page 144

5-24 . Instruments and Controls The vehicle will not pass this inspection if the OBD II (On-Board Diagnostic) system determines that critical emission control systems have not been completely diagnosed by the system. The vehicle would be considered not ready for inspection. This can happen if the 12‐volt battery has recently been replaced or if the 12‐volt battery has run down. The diagnostic system is designed to evaluate critical emission control systems during normal driving. This can take several days of routine driving. If this has been done and the vehicle still does not pass the inspection for lack of OBD II system readiness, your dealer can prepare the vehicle for inspection. Brake System Warning Light 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. If the light comes on and stays on, there is a base brake problem. { 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 comes on briefly when the vehicle is turned on. If it does not come on then, have it fixed so it will be ready to warn if there is a problem.