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:
Switching the display
Press to display or hide the album
title.
If there is additional text, is
displayed.
Press and hold to display the remaining
text.
■USB memory functions
●Depending on the USB memory that is connected to the system, the device itself
may not be operable and certain function ...
For vehicles equipped with mobile communication system
Install an antenna as far as possible away from the ecu
and sensors of the vehicle’s electronic systems.
install an antenna feeder at least 20 cm (7.87 In.) Away
from the ecu and sensors of the vehicle’s electronic systems.
For details of the ecu and sensors locations, refer ...
Inspection procedure
1 Check security indicator light
Remove the security indicator.
check the indicator light, as shown in the illustration and
table.
Standard:
2 Check wire harness (tvip ecu security indicator)
Disconnect the tvip ecu and security indicator connectors.
  ...


