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:
Circuit description
The airbag front rh sensor circuit consists of the airbag sensor assy center
and airbag front rh sensor.
Dtc b1156/b1157/15 is recorded when a malfunction is detected in the airbag
front rh sensor circuit.
Wiring diagram
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How to proceed with troubleshooting
1 Vehicle brought to workshop
2 Customer problem analysis
3 Check and clear dtc
4 Problem symptom confirmation
5 Symptom simulation
6 Dtc check
7 Dtc chart
8 Problem symptoms table
9 Circuit inspection
10 Identification of problem
11 Parts inspection
12 Repair
1 ...
Overhaul
Hint: component:
1. Discharge refrigerant from refrigeration system
sst 07110–58060 (07117–58080, 07117–58090, 07117–78050, 07117–88060,
07117–88070,
07117–88080)
2. Disconnect cooler refrigerant suction hose no.1
Install sst to piping clamp.
Sst 09870–00015
Hint ...


