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:
Audio & visual system
Preparation
Sst
Recomended tools
Equipment
...
Center stop lamp assy
Replacement
1. Remove package tray trim panel assy (w/o rear spoiler)
2. Remove center stop lamp assy (w/o rear
spoiler)
Remove the center stop light assy as shown in the illustlation.
3. Remove center stop lamp assy (w/ rear
spoiler)
Remove the 2 screws.
disconnect th ...
Source voltage drop
The srs is equipped with a voltage–increase circuit (dc–dc converter) in the
airbag sensor assy center
in case the source voltage drops.
When the battery voltage drops, the voltage–increase circuit (dc–dc converter)
functions to increase the
voltage of the srs to normal voltage.
...