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:
Starting system
Inspection
1. Inspect starter assy
Notice:
these tests must be performed within 3 to 5 seconds to
prevent burnout of the coil.
perform the pull–in test.
Remove the nut, then disconnect the lead wire from
terminal c.
Connect the battery to the starter repai ...
Problem symptoms table
Proceed to the reference page shown in the table below for each malfunction
symptom and troubleshoot
each circuit.
Hint:
troubleshooting of the tvip system is based on the premise that the door lock
control system and wireless
door lock control system is operating normally. Accordingly, be ...
Inspection procedure
1 Inspect shift solenoid valve(s1)
Remove the shift solenoid valve s1.
measure the resistance according to the value(s) in the
table below.
Standard:
Connect the positive (+) battery lead to the solenoid connector
terminal, and the negative (–) battery lead to the
solenoid ...


