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:
No sound is heard from speaker in all modes
Wiring diagram
Inspection procedure
1 Check lcd (liquid crystal display) for lighting
Lcd illumination check
turn the ignition switch acc.
Turn the radio receiver assembly on.
Standard: lcd illumination of the radio receiver assembly light.
2 Control fader and ...
What to do if... (Troubleshooting)
If there is a problem with the hands-free system or a Bluetooth® device, first
check the table below.
► When using the hands-free system with a
Bluetooth® device
► When registering/connecting a cellular
phone
► When making/receiving a call
► When using the p ...
Circuit description
The door key lock and unlock switch is built in the door lock motor.
Wiring diagram
Inspection procedure
1 Check door lock
2 Check wire harness (tvip ecu door lock)
Disconnect the tvip ecu and door lock connectors.
check the continuity between the terminals of the t ...


