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:
PCS (Pre-Collision System)
The pre-collision system
uses sensors to detect
objects in the path
of the vehicle. When the
system determines that the
possibility of a frontal collision
with a detectable
object is high, a warning
operates to urge the driver
to take evasive action and
the potential brake pressure
is increased to h ...
How to proceed with troubleshooting
The hand–held tester can be used at step 4, 6, 8 and 9.
1 Vehicle brought to workshop
2 Customer problem analysis
3 Warning light check
4 The dtcs check (present and past dtcs)
5 The dtcs chart
6 Circuit inspection
7 Repair
8 Clear the dtcs (present and past dtcs)
9 The dt ...
Winter driving tips
Carry out the necessary
preparations and inspections
before driving the
vehicle in winter. Always
drive the vehicle in a manner
appropriate to the prevailing
weather conditions.
Pre-winter preparations
Use fluids that are appropriate
to the prevailing outside temperatures.
Engine oil
Engine c ...


