EFI Main Relay (LS430 & SC430)
WARNING: This page does not describe the selected car, but rather 9 other vehicles, including the 2003 Lexus SC 430, 2003 Lexus RX 300, 2003 Lexus LX 470, 2003 Lexus LS 430, and 2003 Lexus IS 300. However, it is still accessible from the selected car via links, so may be relevant.
EFI main relay may also be referred to as EFI relay. Relay is located in fuse/relay box in left side of engine compartment. EFI fuse No. 1 (30-amp) supplies constant battery voltage to one side of EFI main relay. EFI main relay is energized by MREL terminal of Engine Control Module (ECM). When EFI main relay is energized, EFI main relay provides battery voltage to circuit opening relay, EFI fuse No. 2 and data link connector No. 1, and various other electrical components. EFI main relay also provides battery voltage to +B and +B1 terminals of ECM.