Circuit Operation

The fuel injection system controls the engine emission and performance functions as well as providing information to other vehicle systems.


With the ignition switch in RUN or START, battery voltage is supplied through fuse 5, the PGM-FI main relay, and the YEL/BLK wires to the control unit. Battery voltage is supplied at all times through fuse 15 and the YEL/BLU wires to the control unit for memory functions. The control unit is grounded through the BLK wires to G101.


The powertrain control module (PCM) is self-diagnostic and monitors the sensors for irregular signals. See Fuel and Emissions for diagnostic procedures and information about individual sensors.