EFI Main Relay (Corolla)

EFI main relay may also be referred to as EFI relay or F-HTR relay. EFI fuse supplies constant battery voltage to one side of EFI main relay. EFI fuse may also be referred to as F-HTR fuse. When ignition is turned on, voltage is supplied through IGN fuse to other side of EFI main relay. EFI main relay is then energized and provides battery voltage to circuit opening relay, data link connector No. 1, +B terminal of Engine Control Module (ECM) and various other electrical components. For EFI main relay location, see EFI MAIN RELAY LOCATION  table.