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:
Before driving
Observe the following
before starting off in the
vehicle to ensure safety of
driving.
Floor mat
Use only floor mats designed
specifically for vehicles of the
same model and model year as
your vehicle. Fix them securely
in place onto the carpet.
1. Insert the retaining hooks
(clips) into the floor ma ...
Pre–check
1. Pre–check
Check that the cruise control actuator assy, acceleration wire,
accelerator auto drive cable assy, and
link assy are installed correctly and that the wire and link are securely
connected.
check that the operating movement of the acceleration pedal, cruise
control actu ...
Inspection procedure
Hint:
read freeze frame data using the hand-held tester or the obd ii scan tool.
Freeze frame data records the
engine conditions when a malfunction is detected. When troubleshooting, it is
useful for determining whether
the vehicle was running or stopped, the engine was warmed up or not, the ...


