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 Reconfirm dtc
Check the dtc
2 Inspect skid control ecu connector securely connected
3 Inspect skid control ecu connector(ig1 terminal voltage)
In case of using hand–held tester:
check the voltage condition output from the ecu displayed on the
hand–held tester.
O ...
Inspection procedure
Hint:
start the inspection from step 1 in case of using the hand–held tester and start
from step 2 in case of not
using the hand–held tester.
1 Perform active test by hand–held tester(abs warning light)
Check that ”on” and ”off” of the abs warning light can be shown on the
...
Evap monitor (vacuum pressure monitor) (continued)
Preconditions
The monitor will not run unless:
mil is off.
Fuel level is approximately 1/2 to 3/4.
Altitude is 7800 feet (2400 m) or less.*
Engine coolant temperature (ect) is between 40°f and 95°f (4.4 °C and 35
°C).
Intake air temperature (iat) is between 40°f and 95 ...


