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:
Stopping the engine
1 Stop the vehicle.
2 Continuously variable transmission: Shift the shift lever to P.
Manual transmission: Shift the shift lever to N.
3 Set the parking brake. 4 Press the engine switch.
5 Vehicles without a multi-information display: Release the brake pedal (continuously
variable transmission ...
Ecu power source circuit
Circuit description
This circuit provides power to operate the tvip ecu.
Wiring diagram
Inspection procedure
1 Check fuse (ecu–b)
Remove the fuse from the instrument panel j/b.
check the continuity of the fuse.
Standard: continuity
2 Check tvip ecu
Disconnect ...
Bluetooth® (Multimedia system)
Bluetooth®
■When using the Bluetooth® audio system
●In the following conditions, the system may not function.
• If the portable audio player is turned off
• If the portable audio player is not connected
• If the portable audio player’s battery is low
●There may be a ...


