Main Relay (Computer/Fuel System): Description and Operation

PGM-FI Main Relay
The PGM-FI relay contains two separate relays. One is energized whenever the ignition is on which supplies battery voltage to the ECM/PCM, power to the fuel injectors, and power for the second relay. The second relay is energized to supply power to the fuel pump for two seconds when the ignition is switched ON (II), and when the engine is running.