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

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    For your information
    Main Owner’s Manual Please note that this manual applies to all models and explains all equipment, including options. Therefore, you may find some explanations for equipment not installed on your vehicle. All specifications provided in this manual are current at the time of printing. Howeve ...

    Inspection procedure
    1 Check door lock 2 Check wire harness (tvip ecu door lock) Disconnect the tvip ecu and door lock connectors.  check the continuity between the terminals of the tvip ecu and door lock connectors, as shown in the illustration and table. Standard: 3 Check wire harness ...

    Basic inspection
    When the malfunction is not confirmed in the dtc check, troubleshooting should be carried out in all the possible circuits considered as causes of the problem. In many cases, by carrying out the basic engine check shown in the following flowchart, the location causing the problem can be found ...