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:
Chassis
On–vehicle inspection
1. Inspect steering linkage
check the steering wheel freeplay .
check the steering linkage for looseness or damage.
Check that the tie rod ends do not have excessive play.
Check that the dust seals and boots are not damaged.
Chec ...
Replacement
1. Remove engine under cover rh
2. Drain coolant
3. Remove fan and generator v belt
4. Remove generator assy
Disconnect the wire clamp from the wire clip on the rectifire
end frame.
remove the rubber cap and nut, and disconnect the alternator
wire.
disconnect the ...
Diagnostic trouble code chart
Notice:
when removing the part, turn the ignition switch to off.
Hint:
using sst 09843–18040, it connect the terminal tc and cg of dlc3.
If any abnormality is not found when inspecting parts, inspect the ecu and
ground points for poor contact.
If a malfunction code is displayed during ...


