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:
Source voltage drop
The srs is equipped with a voltage–increase circuit (dc–dc converter) in the
airbag sensor assy center
in case the source voltage drops.
When the battery voltage drops, the voltage–increase circuit (dc–dc converter)
functions to increase the
voltage of the srs to normal voltage.
...
Amplifier antenna assy
Replacement
Hint: components:
Remove roof headlining assy
Notice:
do not bend the roof headlining assy.
Hint:
refer to the procedure from ”remove roof headlining assy” of roof
headlining assy.
Remove the related parts as long as the amplifier antenna assy can be
removed. ...
Inspection
1. Power window system circuit
2. Inspect power window regulator master switch assy
Inspect the master switch continuity.
[Driver’s switch (window unlock and lock)]
Standard:
[Front passenger’s switch (window unlock)]
standard:
[Front passenger’s switch (window lock)]
...


