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:
How to proceed with troubleshooting
The hand–held tester can be used at step 4, 6, 8 and 9.
1 Vehicle brought to workshop
2 Customer problem analysis
3 Warning light check
4 The dtcs check (present and past dtcs)
5 The dtcs chart
6 Circuit inspection
7 Repair
8 Clear the dtcs (present and past dtcs)
9 The dt ...
Safety Connect
*: If equipped
Safety Connect is a subscription-
based telematics
service that uses Global
Positioning System (GPS)
data and embedded cellular
technology to provide
safety and security features
to subscribers. Safety Connect
is supported by Toyota's
designated response
center, which operates 24
hour ...
PDA (Proactive driving assist)
When a detectable object
is detected, the
proactive driving assist
operates the brakes and
steering wheel to help prevent
the vehicle from
approaching too close to
the object.
WARNING
■For safe use
Driving safely is solely the responsibility
of the driver.
The proactive driving assist is
design ...


