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

Main Relay Operation:

The main relay is mounted behind the fuse box under the dash. The unit houses two relays. One relay is used to supply power to the ECU, the injectors and to the second relay. The first relay is energized whenever the ignition switch is turned on. The second relay is energized for two seconds when the ignition is turned on and when the engine is running, to supply power to the fuel pump.