Ford P0603 OBD-II Trouble Code Definition: P0603 ECM Power Supply Circuit P0603 Ford OBD-II Trouble CodeDescription: OBD Trouble Code P0603 Internal Control Module Keep Alive Memory (KAM) Error What does the code mean? OBD-ii Code P0603 definition: Battery voltage is supplied to the ECM/PCM even when the ignition switch is turned OFF for the ECM/PCM memory […]