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:
Circuit description
The vehicle equipped with abs detects a vehicle speed using the stability
control ecu and wheel speed
sensor. This sensor monitors a wheel rotation speed and sends the signal to the
ecu.
The stability control ecu converts these wheel speed signals into a 4–pulse
signal and outputs it to ...
Warning lights and indicators
The warning lights and indicators on the instrument cluster and center panel
inform the driver of the status of the vehicle’s various systems.
For the purpose of explanation, the following illustration displays all warning
lights and indicators illuminated.
► Vehicles with a drive moni ...
Shift lock system (atm)
On–vehicle inspection
1. Check shift lock operation
shift the shift lever to p position.
turn the ignition switch to lock.
check that the shift lever cannot be shifted to any other
positions other than p.
turn the ignition switch to on, depress the brake pedal ...


