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:

    On–vehicle inspection
    1. Inspect sliding roof function  check the slide opening operation (manual).  Turn the ignition switch on.  When keeping operating the sliding roof switch to the open side, check that the roof glass will slide and be fully opened.  check the slide closing ...

    Exterior
    Doors Locking/unlocking Opening/closing the side windows Locking/unlocking by using the mechanical key*1 Warning messages Trunk Opening from inside Opening from outside Warning messages Outside rear view mirrors Adjusting the mirror angle Folding the mirrors Defogging the mirrors*2 ...

    Circuit description
    The o/d main switch (transmission control switch) is a momentary type switch. When pressing the o/d main switch, the o/d off indicator light lights up and the ecm prohibits shifting into o/d, and when pressing it once again, the o/d off indicator light goes off and the ecm allows shifting in ...