LEMON Manuals: Even more car manuals for everyone: 1960-2025
Home >> Lexus >> 2003 >> RX 300 FWD >> Repair and Diagnosis >> Engine Performance >> System >> Engine Controls - System & Component Testing >> Computerized Engine Controls >> ECM Power Source Circuit (Ignition On) >> Circuit Description
October 30: LEMON manuals on a temporary server, it is slow and having issues, download the manuals you need! Later in November we will switch back to the fast server.

Circuit Description

When ignition switch is turned on, 9-14 volts is applied to the terminal IGSW at ECM main relay control circuit, sending a signal to terminal MREL at ECM, which then switches EFI main relay on. When ignition is turned off, ECM will keep EFI main relay on for 2 seconds or less in order to reset Idle Air Control (IAC) valve.