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:
Continuously variable transmission
(vehicles with paddle shift
switches)
Select the shift position
depending on your purpose
and situation.
Shift position purpose
and functions
P - Parking the vehicle/
starting the engine
R - Reversing
N - Neutral
(Condition in which the
power is not transmitted)
D - Normal driving*
M - 10-speed sport sequential
shiftmatic mode driving
* ...
Inspection procedure
1 Check courtesy lamp switch
Check the courtesy switch, as shown in the illustration
and table.
Standard:
2 Check wire harness (integration relay door courtesy sw)
Disconnect the integration relay and door courtesy connectors.
check the continuity between th ...
Chassis
On–vehicle inspection
1. Inspect steering linkage
check the steering wheel freeplay .
check the steering linkage for looseness or damage.
Check that the tie rod ends do not have excessive play.
Check that the dust seals and boots are not damaged.
Chec ...


