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:
Replacement
1. Remove engine under cover rh
2. Remove cylinder head cover no.2
Remove the 2 screw, 3 clips and engine under cover.
3. Remove fan and generator v belt
Turn the v–ribbed belt tensioner slowly clockwise and
loosen it. Then, remove the fan and generator v belt and
put back ...
Checking the messages
1 Display the “Message Inbox” screen.
2 Select the desired message from the list.
3 Check that the message is displayed.
1 E-mails: Select “Mark Unread” or “Mark Read” to mark mail unread or read on
the message inbox screen.
This function is available when “Update Message Read S ...
Inspection procedure
1 Check wire harness(airbag sensor assy center – front seat inner
belt assy lh)
Disconnect the negative (–) terminal cable from the battery,
and wait at least for 90 seconds.
disconnect the connectors between the airbag sensor
assy center and the front seat inner belt assy ( ...


