EG–465 ENGINE – 2JZ–GE ENGINE TROUBLESHOOTING ECM Power Source Circuit CIRCUIT DESCRIPTION When the ignition switch is turned on, battery voltage is applied to the terminals IGSW of the ECM, and the main relay control circuit in the ECM sends a signal to the terminal M–REL of the ECM, switching on the main relay. This signal causes current to flow to the coil, closing the contacts of the main relay and supplying power to the terminal +B of the ECM. If the ignition switch is turned off, the ECM continues to switch on the main relay for a maximum of 2 seconds for the initial setting of the IAC valve. Engine Control Module EFI No.1 Fuse EFI Main Relay +B M-REL AM2 Fuse Ignition Switch IGSW Main Relay Control Circuit Battery E1 P18745 WIRING DIAGRAM Engine Control Module W-R 2 3 Ignition Switch IGN 1J 1E J/B No.1 B-O >>I11 B-O 1 IGSW E10 E1 B-R 31 +B E10 B-Y 2 2 3 5 B-R >>EA3 B+ 2 2 1 GR >>EA1 GR 24 M-REL E10 EFI Main Relay R:B No.2 AM2 EFI No.1 R/B No.2 W B BR 69 E1 E9 1 2A Battery P18746