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:
Seat heaters
Press the switch.
1 High temperature
2 Low temperature
The indicator light comes on when the switch is on.
■The seat heaters can be used when
► Vehicles without a smart key system
The engine switch is in the “ON” position.
►Vehicles with a smart key system
The engine ...
Driving assist systems
To keep driving safety and
performance, the following
systems operate automatically
in response to various
driving situations. Be
aware, however, that these
systems are supplementary
and should not be relied
upon too heavily when operating
the vehicle.
Summary of the driving
assist systems
■ ABS ( ...
Inspection procedure
1 Check seat position air bag sensor
Sst 09843–18040
Turn the ignition switch to on, and wait at least for 20 seconds.
clear the dtc stored in memory .
turn the ignition switch to lock, and wait at least for 20
seconds.
turn the ignition switch to on, and wait at ...


