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:
Exhaust gas precautions
Harmful substance to the
human body is included in
exhaust gases if inhaled.
WARNING
Exhaust gases include harmful
carbon monoxide (CO), which is
colorless and odorless. Observe
the following precautions.
Failure to do so may cause
exhaust gases enter the vehicle
and may lead to an accident
caused ...
Starting the engine
1 Continuously variable transmission: Ensure that the shift lever is in P and
depress the brake pedal.
Manual transmission: Shift the shift lever to N and depress the clutch pedal.
2 Touch the Toyota emblem side of the electronic key to the engine switch.
When the electronic key is detected, a ...
Problem symptoms table
Hint:
use the table below to help determine the cause of the problem. The numbers
indicate the priority of the
likely cause of the problem. Check each part in order. If necessary, replace
these parts.
1. Headlamp and tail lamp
2. Front fog lamp system
3. Turn signal and hazard warni ...


