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:
Circuit description
Refer to dtc p0120
Dtc no.
Dtc detection condition
Trouble area
P0121
The following condition is met 4 times. After the vehicle speed
has exceeded 19 mph (30 km/h) once, the throttle position
sensor output value is out of normal range when the throttle
...
Exterior
Doors
Locking/unlocking
Opening/closing the side windows
Locking/unlocking by using the mechanical key*1
Warning messages
Trunk
Opening from inside
Opening from outside
Warning messages
Outside rear view mirrors
Adjusting the mirror angle
Folding the mirrors
Defogging the mirrors*2
...
General maintenance
Listed below are the general
maintenance items that
should be performed at the
intervals specified in the
"Owner's Warranty Information
Booklet" or "Owner's
Manual Supplement/Scheduled
Maintenance Guide". It
is recommended that any
problem you notice should
be brought to the attention
of your Toyota ...


