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:
Glossary of sae and toyota terms
This glossary lists all sae–j1930 terms and abbreviations used in this manual
in compliance with sae recommendations,
as well as their toyota equivalents.
...
Steering column
Service data
Torque specification
Power steering
Service data
Torque specification
: For use without sst ...
How to proceed with troubleshooting
The hand–held tester can be used at step 3, 4, 6, 9.
1 Vehicle brought to workshop
2 Customer problem analysis
3 Connect the obd ii scan tool or hand–held tester to dlc3
4 Check and clear dtc and freeze frame data
5 Visual inspection
6 Setting the check mode diagnosis
7 Proble ...


