2011 Chevrolet Express 1500 Cargo Owner's Manual - Page 141

Instruments and Controls 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 9‑40. 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. 5-23 Emissions Inspection and Maintenance Programs Some state/provincial and 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 vehicle may not pass inspection if: . The malfunction indicator lamp is on with the engine running, or if the light does not come on when the ignition is turned to ON/RUN while the engine is off. The critical emission control systems have not been completely diagnosed by the system. This can happen if the battery has recently been replaced or if the battery has run down. The diagnostic system evaluates 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, your dealer can prepare the vehicle for inspection. . The DLC is under the instrument panel to the left of the steering wheel. See your dealer if assistance is needed.