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

PURPOSE/OPERATION
When the ignition switch is turned on, battery voltage is applied from the ignition switch to the engine control module, turning ON the ignition power transistor and energizing the multi-point fuel injection control relay coil. This turns ON the multi-point fuel injection control relay switch, and supplies power from the battery to the engine control module through the multi-point fuel injection control relay switch.