Toyota Corolla (E120) 2002–2008 Repair Manual / Diagnostics / Sfi system / Mil circuit / Circuit description
Toyota Corolla (E120): Circuit description
The ignition switch provides circuit power and the ecm provides the circuit ground that illuminates the mil.
Mil operation is checked visually: it should be illuminated when the ignition is first turned on. If the mil is off all of the time or on all of the time, use the procedure below to troubleshoot it. The mil is used to indicate the ecm’s detection of a vehicle malfunction.
Follow this procedure using the hand–held tester or an obd ii scan tool to determine the cause of the problem and to check the mil.
Wiring diagram

Other materials:
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. ...
Inspection procedure
1 Check fuse(ecu–ig)
Remove the ecu–ig fuse from the instrument panel j/b.
check the continuity of the ecu–ig fuse.
Ok: continuity
2 Inspect terminal voltage(b)
Remove the cruise control ecu assy with connector still
connected.
turn the ignition switch ...
Disabling the TRAC system
If the vehicle gets stuck in mud, dirt or snow, the TRAC system may reduce power
from the engine to the wheels. Pressing
to turn the system off may make it
easier for you to rock the vehicle in order to free it.
To turn the TRAC system off, quickly press and release
.
The “TRAC OFF” ind ...


