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 Input signal check
See the input signal check on page 05–745.
check the indicator light when the clutch pedal is depressed.
Ok:
the indicator light goes off when the clutch pedal is
depressed.
2 Inspect terminal voltage(d)
Turn the ignition switch to on.
&n ...
Emergency flashers
The emergency flashers are used to warn other drivers when the vehicle has
to be stopped in the road due to a breakdown, etc.
Press the switch.
All the turn signal lights will flash.
To turn them off, press the switch once again.
■Emergency flashers
If the emergency flashers are used ...
Engine immobilizer system
The vehicle's keys have
built-in transponder chips
that prevent the engine from
starting if a key has not
been previously registered
in the vehicle's on-board
computer.
Never leave the keys inside
the vehicle when you leave
the vehicle.
This system is designed to
help prevent vehicle theft
but doe ...


