Toyota Corolla (E120): Circuit description

When the ignition switch is turned on, battery positive voltage is applied to the coilwhich closes the contacts of the efi main relay (marked: efi) and supplies power to terminal +b of the ecm.

This signal causes current to flow to the coil, closing the contacts of the efi relay and supplying power to terminal +b of the ecm.

If the ignition switch is turned off, the ecm continues to switch on the efi relay for a maximum of 2 seconds for the initial setting of the isc valve.

Wiring diagram

Inspection procedure

    Share this page:

    Other materials:

    Battery
    Check the battery as follows. ■ Battery exterior Make sure that the battery terminals are not corroded and that there are no loose connections, cracks, or loose clamps. 1 Terminals 2 Hold-down clamp ■Before recharging When recharging, the battery produces hydrogen gas which is ...

    Customizing vehicle features
    It is possible to customize the language and Eco Driving Indicator Light settings using the “DISP” switch. When customizing vehicle features, ensure that the vehicle is parked in a safe place with the shift the shift lever to P (continuously variable transmission) or N (manual transmissio ...

    Front passenger occupant classification system
    Your vehicle is equipped with a front passenger occupant classification system. This system detects the conditions of the front passenger seat and activates or deactivates the devices for the front passenger. 1 SRS warning light 2 Seat belt reminder light 3 “AIR BAG OFF” indicator light ...