Autel AL439 OBDII and Electrical Test Tool Works on ALL 1996 and newer vehicles(OBDII & CAN)-domestic and import Features the unique patented One-Click I/M Readiness Key for quick State Emissions readiness check and drive cycle verification Easy-to-read AVOmeter allows you to test voltage, continuity and current at the fingertip Capable of diagnosing 12V charging systems, starting systems and condition of discharged battery Easily determines the cause of the Check Engine Light (MIL)