2005 Subaru Impreza Owner's Manual - Page 160

Instruments and controls checked. Unless checked and properly repaired, the seatbelt pretensioners and/or SRS airbag will not operate properly in the event of a collision, which may increase the risk of injury. Flashing or flicking of the indicator light No illumination of the warning light when the ignition switch is first turned to the "ON" position Continuous illumination of the warning light Illumination of the warning light while driving If this light comes on steadily or blinks while the engine is running, it may indicate that there is a problem or potential problem somewhere in the emission control system. If the light comes on steadily: If the light comes on steadily while driving or does not go out after the engine starts, an emission control system malfunction has been detected. You should have your vehicle checked by an authorized SUBARU dealer immediately. NOTE CHECK ENGINE warning light/ Malfunction indicator lamp This light also comes on when the fuel filler cap is not tightened until it clicks. If you have recently refueled your vehicle, the cause of the CHECK ENGINE warning light/malfunction indicator lamp coming on could be a loose or missing fuel filler cap. Remove the cap and retighten it until it clicks. Make sure nothing is interfering with the sealing of the cap. Tightening the cap will not make the CHECK ENGINE warning light turn off immediately. It may take several driving trips. If the light does not go out, take your vehicle to your authorized SUBARU dealer immediately. If the light is blinking: If the light is blinking while driving, an engine misfire - CONTINUED - If the CHECK ENGINE light comes on while you are driving, have your vehicle checked/repaired by your SUBARU dealer as soon as possible. Continued vehicle operation without having the emission control system checked and repaired as necessary could cause serious damage, which may not be covered by your vehicle's warranty. 3-21