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:
Seat belt warning lamp for front passenger’s seat
does not flash
Wiring diagram
Inspection procedure
1 Inspect combination meter assy
Ground terminal c9–11 on the combination meter side.
check that the warning lightlights up.
Ok: warning light lights up.
2 Inspect passenger seat belt warning lamp assy
Ground terminal c9– ...
Driving monitor
■ Switching the display
Items displayed can be switched by pressing the “DISP” switch.
■ Average fuel consumption
Displays the average fuel consumption since the function was reset.
• Press and hold the “DISP” switch to reset when the average fuel consumption
is display ...
Inspection procedure
1 Inspect dlc3 terminal voltage
Turn the ignition switch to on.
measure voltage between terminals 13 (tc) and 4 (cg) of
dlc3.
Ok:
voltage: 10 – 16 v
2 Check harness and connector(between cruise control ecu assy
and dlc3)
Check for open and short circuit in harness ...


