Signal Function

The FICM requires a 12-volt power source. The FICM receives power from the vehicle batteries through the FICM relay contacts each time the ignition switch is turned to the ON position. The powertrain control module (PCM) communicates with the FICM using the controller area network (CAN) protocol. The CAN protocol is an international standards organization (ISO) standard for serial data communication. The CAN protocol standard includes a physical layer using differential transmission on a twisted pair of wires and a data link layer that defines different message types, arbitration rules for bus access, methods for fault detection and fault confinement.