2012 Buick LaCrosse Owner Manual - Page 137

Instruments and Controls The following may correct an emissions system malfunction: . 5-19 Check that the fuel cap is fully installed. See Filling the Tank on page 9‑55. 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, 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 will require at least one full tank of the proper fuel to turn the light off. See Recommended Fuel on page 9‑53. 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. The DLC is under the instrument panel next to the steering wheel. See your dealer if assistance is needed. The vehicle may not pass inspection if: . . Emissions Inspection and Maintenance Programs Some local governments may have programs to inspect the on-vehicle emission control equipment. For the inspection, the emission system test equipment is connected to the vehicle's Data Link Connector (DLC). The malfunction indicator lamp is on while the vehicle is running. The vehicle is in ON/RUN for keyed access, or service only mode for keyless access and the malfunction indicator lamp does not come on. See your dealer for assistance in verifying proper operation of the malfunction indicator lamp.