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:
Overhaul
Hint: components:
1. Remove rear wheel
2. Remove spare wheel cover assy
3. Remove rear floor finish plate
4. Remove luggage compartment trim cover inner lh
5. Remove rear shock absorber with coil spring
Support the rear axle beam with jack.
Remove the 2 nuts and bolt.
...
Inspection procedure
1 Check p squib circuit(airbag sensor assy center – instrument
panel passenger airbag assy)
Disconnect the negative (–) terminal cable from the battery,
and wait at least for 90 seconds.
disconnect the connectors between the airbag sensor
assy center and the instrument panel ...
Engine (ignition) switch (vehicles
with a smart key system)
Performing the following
operations when carrying
the electronic key on your
person starts the engine or
changes engine switch
modes.
Starting the engine
1. Check that the parking brake
is set.
2. Check that the shift lever is in
P.
3. Firmly depress the brake
pedal.
and a message will be display ...


