2013 Buick LaCrosse Owner Manual - Page 121

Instruments and Controls This light comes on during a malfunction in one of two ways: Light Flashing: A misfire condition has been detected. A misfire increases vehicle emissions and could damage the emission control system on the vehicle. Diagnosis and service might be required. To prevent more serious damage to the vehicle: ... 5-17 Light On Steady: An emission control system malfunction has been detected on the vehicle. Diagnosis and service might be required. The following may correct an emissions control system malfunction: . or stumbling on acceleration. These conditions might go away once the engine is warmed up. If one or more of these conditions occurs, change the fuel brand used. It may require at least one full tank of the proper fuel to turn the light off. See Recommended Fuel on page 9‑47. If none of the above have made the light turn off, your dealer can check the vehicle. The dealer has the proper test equipment and diagnostic tools to fix any mechanical or electrical problems that might have developed. Reduce vehicle speed. Avoid hard accelerations. Avoid steep uphill grades. If the vehicle is towing a trailer, reduce the amount of cargo being hauled as soon as it is possible. . Check that the fuel cap is fully installed. See Filling the Tank on page 9‑50. The diagnostic system can determine if the fuel cap has been left off or improperly installed. A loose or missing fuel cap allows fuel to evaporate into the atmosphere. A few driving trips with the cap properly installed should turn the light off. Check that good quality fuel is used. Poor fuel quality causes the engine not to run as efficiently as designed and may cause stalling after start-up, stalling when the vehicle is changed into gear, misfiring, hesitation on acceleration, Emissions Inspection and Maintenance Programs Depending on where you live, your vehicle may be required to participate in an emission control system inspection and maintenance program. For the inspection, the emission system test equipment will likely connect to the vehicle's Data Link Connector (DLC). If the light continues to flash, find a safe place to stop and park the vehicle. Turn the vehicle off, wait at least 10 seconds, and restart the engine. If the light is still flashing, follow the previous steps and see your dealer for service as soon as possible.