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:
Toyota Safety Sense 3.0
The Toyota Safety Sense 3.0
consists of the driving
assist systems and contributes
to a safe and comfortable
driving experience:
WARNING
■Toyota Safety Sense 3.0
The Toyota Safety Sense 3.0
operates under the assumption
that the driver will drive safely,
and is designed to help reduce
the impact t ...
How to proceed with troubleshooting
Hint:
carry out troubleshooting in accordance with the procedures on the following
page. Here, only the basic
procedures are shown. Details are provided in the diagnostics section, showing
the most effective methods
for each circuit. Confirm the troubleshooting procedures first for the releva ...
Alarm
The alarm uses light and
sound to give an alert when
an intrusion is detected.
The alarm is triggered in the
following situations when
the alarm is set:
A locked door or trunk is
unlocked or opened in any
way other than using the
entry function (if equipped),
wireless remote control,
mechani ...


