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:
Do-it-yourself service precautions
If you perform maintenance by yourself, be sure to follow the correct procedure
as given in these sections.
CAUTION
The engine compartment contains many mechanisms and fluids that may move suddenly,
become hot, or become electrically energized. To avoid death or serious injury,
observe t ...
Overhaul
Hint: component:
1. Discharge refrigerant from refrigeration system
sst 07110–58060 (07117–58080, 07117–58090, 07117–78050, 07117–88060,
07117–88070,
07117–88080)
2. Disconnect cooler refrigerant suction hose no.1
Install sst to piping clamp.
Sst 09870–00015
Hint ...
Combination meter assy
Overhaul
Hint: components:
1. Remove meter hood sub–assy
2. Remove combination meter assy
Remove the screw.
disengage the 2 clips as shown in the illustration.
disconnect the connector, then remove the combination
meter.
3. Remove combination meter glass
Di ...


