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

ECU battery voltage is supplied to the BATT terminal through the STOP fuse (15A), at all times. The Ignition Switch provides voltage to terminals +B and +B1 of the ECU through the IGN fuse (10A), when the ignition switch is turned on. System battery voltage must be at least 10 volts in order to operate ECU functions.