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:
Exhaust gas precautions
Harmful substance to the human body is included in exhaust gases if inhaled.
CAUTION
Exhaust gases include harmful carbon monoxide (CO), which is colorless and odorless.
Observe the following precautions.
Failure to do so may cause exhaust gases enter the vehicle and may lead to an
accident c ...
Engine mechanical
Preparation
Sst
Recomended tools
Ssm
Equipment
Exhaust
Preparation
Equipment
...
Definition of terms
Term
Definition
Monitor description
Description of what the ecm monitors and how it detects malfunction
(monitoring purpose and its details).
Related dtcs
Diagnostic code
Typical enabling condition
Preconditions that allow the ecm to detect m ...


