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:
Inspection procedure
1 Check operation(starter)
Check that the starter operates normally and that the engine starts.
2 Input signal check
See input signal check on page 05–745.
check the indicator light when shifting into except d position.
Ok:
the indicator light goes off when shifting ...
Overhaul
1. Precaution
2. Disconnect battery negative terminal
3. Inspect place front wheels facing straight ahead
4. Remove horn button assy
Notice:
if the airbag connector is disconnected with the ignition
switch being at on, dtcs will be recorded.
using a torx socket wrench, loosen the ...
Seat belt warning lamp for front passenger’s seat
does not flash
Wiring diagram
Inspection procedure
1 Inspect combination meter assy
Ground terminal c9–11 on the combination meter side.
check that the warning lightlights up.
Ok: warning light lights up.
2 Inspect passenger seat belt warning lamp assy
Ground terminal c9– ...


