Serial Communications Interface (Sci)

SCI circuit is used by PCM to send data to and receive data and sensor activation signals from scan tool. Scan tool uses signals sent on SCI to display fault messages or DTCs, sensor voltages and device states (On/Off). Scan tool uses SCI to send solenoid and switch activation commands to PCM so that devices and circuits can be tested. SCI is also used to reset Service Reminder Indicator (SRI) light on some vehicles and to write SRI mileage to PCM.