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:
Replacement
1. Remove engine under cover rh
2. Drain coolant
3. Remove front wheel rh
4. Remove cylinder head cover no.2
Remove the 2 nuts, 2 clips and cylinder head cover.
5. Remove fan and generator v belt
Turn the v–ribbed belt tensioner slowly clockwise and
loosen it. Then, remove ...
Inspection procedure
1 Check side squib(rh) circuit(airbag sensor assy center – front
seat airbag assy rh)
Disconnect the negative (–) terminal cable from the battery,
and wait at least for 90 seconds.
disconnect the connectors between the front seat airbag
assy (rh) and the airbag sensor assy center. ...
Malfunction in water temperature receiver gauge
Wiring diagram
Inspection procedure
1 Read value of hand–held tester
Check output value of ecm.
Connect the hand–held tester to dlc3.
Turn the ignition switch to on and push the hand–held tester main
switch on.
Select the data list mode on the hand–he ...


