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
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)]
...
Problem symptoms table
When the malfunction code is not confirmed in the diagnostic trouble code
check and the problem still can
not be confirmed in the basic inspection, proceed to this problem symptoms
tables and troubleshoot according
to the numbered order given below.
*: A/t only ...
Inspection procedure
1 Inspect dlc3 terminal voltage(ts terminal)
Turn the ignition switch to on.
measure voltage between terminals ts and cg of dlc3.
Ok:
voltage: 10 – 14 v
2 Check harness and connector(dlc3 – body ground)
Check for open and short circuit in harness and connector between
...


