Toyota Corolla (E120) 2002–2008 Repair Manual / Diagnostics / Sfi system / Ecm power source circuit / Circuit description
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

Other materials:
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 ...


