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:
Cd sound skips
Inspection procedure
1 Disc cleaning
Disk cleaning
) if the disk gets dirty, clean the disk by wiping the surface
from the center to outside in the radial directions
with a soft cloth.
Notice:
do not use a conventional record cleaner or anti–static preservative.
Standard: ...
Inspection procedure
Hint:
if dtcs p0115, p0116, p0117, p0118 and p0125 are output
simultaneously, the engine coolant temperature
sensor circuit may be open or short. Perform the troubleshooting of dtc
p0115, p0117 or
p0118 first.
Read freeze frame data using the hand-held tester or the obd ii scan
to ...
Sound quality is bad only when cd is played(volume is
too low)
Inspection procedure
1 Replace cd with another and recheck
Replace the cd with another and recheck.
Check the installation condition of the radio receiver assembly.
Standard: malfunction disappear.
Check and replace radio receiver assy ...


