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:
USB charging port (if
equipped)
The USB charging port are used
to supply 3.0 A of electricity at 5
V to external devices.
The USB charging port are for
charging only. They are not
designed for data transfer or
other purposes.
Depending on the external
device, it may not charge properly.
Refer to the manual
included with the dev ...
When using a child
restraint system
■ When installing a child
restraint system to a front
passenger seat
For the safety of a child, install a
child restraint system to a rear
seat. When installing a child
restraint system to a front passenger
seat is unavoidable,
adjust the seat as follows and
install the child restraint system:
M ...
Malfunction in water temperature receiver gauge
Wiring diagram
Inspection procedure
1 Read value of hand–held tester
Check output value of ecm.
Connect the hand–held tester to dlc3.
Turn the ignition switch to on and push the hand–held tester main
switch on.
Select the data list mode on the hand–he ...


