2008 Chevrolet HHR Owner's Manual - Page 172

When the Light Flashes First and Then is Solid This indicates that there may be a problem with the Tire Pressure Monitor System. The light will flash for about a minute and then stay on solid for the remainder of the ignition cycle. This sequence will repeat with every ignition cycle. See Tire Pressure Monitor System on page 5-61 for more information. The check engine light comes on to indicate that there is an OBD II problem and service is required. Malfunction Indicator Lamp Check Engine Light A computer system called OBD II (On-Board Diagnostics-Second Generation) monitors operation of the fuel, ignition, and emission control systems. It makes sure that emissions are at acceptable levels for the life of the vehicle, helping to produce a cleaner environment. Malfunctions often are indicated by the system before any problem is apparent. This can prevent more serious damage to your vehicle. This system is also designed to assist your service technician in correctly diagnosing any malfunction. Notice: If you keep driving your vehicle with this light on, after a while, the emission controls might not work as well, your vehicle's fuel economy might not be as good, and the engine might not run as smoothly. This could lead to costly repairs that might not be covered by your warranty. 3-40