2009 Cadillac XLR-V Owner's Manual - Page 172

Tire Pressure Light For vehicles with the tire pressure light, it comes on briefly when the engine is started. If it does not, have the vehicle serviced by your dealer/retailer. If the system is working normally the indicator light then goes off. 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. This comes on briefly while starting the engine. If it does not come on, have the vehicle serviced by your dealer/retailer. This light also comes on when one or more of the tires is significantly underinflated. A tire pressure message in the Driver Information Center (DIC) can accompany the light. See DIC Warnings and Messages on page 3-60 for more information. Stop and check the tires as soon as it is safe to do so. If underinflated, inflate the tire to the proper pressure. See Tires on page 6-46 for more information. If a problem is detected with the Tire Pressure Monitor System, this light flashes for approximately 60 seconds and then stays on for the remainder of the ignition cycle. See Tire Pressure Monitor System on page 6-55 for more information. 3-50 If the check engine light comes on and stays on, while the engine is running, this indicates that there is an OBD II problem and service is required.