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:
Brake
On–vehicle inspection
1. Inspect brake line pipes and hoses
Hint:
work in a well–lighted area. Turn the front wheels fully to the
right or left before begining.
check all the brake lines and hoses for:
damage
wear
deformation
cracks
corrosion
leaks
bends
twi ...
Electronic control
Removal and installation of battery terminal
before performing electrical work, disconnect the
battery negative (–) terminal cable beforehand so
as to prevent burnt–out damage by short.
When disconnecting and installing the terminal
cable, turn the ignition switch an ...
How to proceed with troubleshooting
1 Vehicle brought in
2 Customer problem analysis check and symptom check
3 Problem symptoms table
Without applicable symptoms, proceed to ”a”
with applicable symptoms, proceed to ”b”
4 Perform troubleshooting in the following method, depending on
malfunction symptom ...