Beginning on January 1, 1996, the federal government required manufacturers to equip all U.S.-bound vehicles with a standardized diagnostic system, known as On-Board Diagnostics, Series II. This system monitors all of the major electrical components that affect the CO2 emissions of the engine, and triggers a "Check Engine" light when it detects a failure. The first step in diagnosing a "Check Engine" light on your 2012 Mitsubishi Lancer is finding the OBD-II connection port-- also known as the data link connector.
Finding the OBD-II Connector
Open the driver-side door and adjust the seat back as far as it will go. Look under the driver side of the dashboard, to the left of the steering wheel, and find the trapezoid-shaped, male electrical receptacle. This is the OBD-II data link connector -- the connector that allows you access to the information within the OBD-II system by plugging a code scanner into it.