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:
Installation with LATCH system
1 Widen the gap between the seat cushion and seatback slightly.
► Type A
2 Latch the hooks of the lower straps onto the LATCH anchors. If the child restraint
has a top tether strap, the top tether strap should be latched onto the top tether
strap anchor.
For owners in Canada: The symbol ...
If the engine will not start
If the engine will not start
even though correct starting
procedures are being followed, consider
each of the following
points:
The engine will not start
even though the starter
motor operates normally.
One of the following may be the
cause of the problem:
There may not be sufficient
fuel in the ...
Monitor description
Dtc p0451, p0452 or p0453 is recorded by the ecm when the vapor pressure
sensor malfunctions.
P0451
The ecm senses pressure in the fuel tank using the vapor pressure sensor. The
ecm supplies the sensor
with a regulated 5 v reference–voltage and the sensor returns a signal voltage
betwee ...


